The present investigations are concerned with following question: a. By what way does the hight effect on the process of the root formation of potatoes ? b. How does a variation in the intensity of light affect the magnitude of the longitudinal electrical polarity ? The electrical measurements were taken at every 5 milimeters betwen apex of lateral bud and root tip. The contact on the upper side was connected to the stem, and the contact on the lower side was used as the variable. This method and materials must be well adapted to this special test. The data represented by the Curves (Fig 2-Fig 4) demonstrate the following facts: This magnitude of the electrical response is dependent on the intensity of light stimulation applied. The electrical polarity is established prior to the unequal distribution of the growth hormon. Increase in the electric polarities is associated with a steady progress in ripening of the root primordia. This increase in polarities is thought to be brought about by nuclear activities leading to cell division. In the evaluation of our data it should be considered that the zone of endogrowth gets into the base of root from the apex of bud at the very early stage.

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Our experiment concerning the effect of light stimulation and action current on the sweet-potato was carried on in conjunction with a study related to bud inhibition mechanism. Statements concerning the effect of inhibitory substance in apex upon lateral buds have been generally accepted but it seemed to us somewhat ambigous. As it is no doubt that the growth of lateral buds involves the physiology of the root primordia, it seemed desirable to determine whether the increased conductivity obtained with decapitated sedling is primarily due to the facilitation of exchange of favorable materials and water through the bud and root primordia. The sequence of the responses of the swet-potatoes to heat-stimulation are summarized. The nature of this experiment is such that the magnitude of action current after the removal of apex is of prime significance. A conduction of excitement betwen lateral bud and roots is established immediately after removal of apex (0.3 cm∼0.5 cm) without any morphological evidence for growth promotion (Fig. (B) and Fig. (D)). Interesting results come from Fig.3 (D). The action current is in parallel with that of the rest before and after decapitation of apical region.

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The authors made an experimental study on tillering in paddy rice under the cultural conditions of direct sowing and transplanting. With variety Rikuu 132, cultures by both of these methods were practiced in 1947. Sowings were done on May 5. Transplantings were made on June 9 in one plot and on June 19 in another. Each plant was given a space of 1.2×0.4 shaku either in direct-sown or in transplanted plot. The numbers used for investigations per Plot were 40. In the direct-sown culture the first tiller appeared quite usually from the 2nd node (the 1st normal-leaf node) on main stem, while in the transplanted one some lower nodes remained dormant in most cases and the frst tiller appeared usually from the 4th or 5th node. Moreover, in the former, tillers appeared quite regularly in order from the lowest one to the succeeding upper ones, while in the latter, such regularity was not the case with some lower ones. In the former, however, the last tiller on main stem was that from the 9th node, while in the latter the 10th node shooted it. Lateral tillers in the transplanted culture were apparently less in number than in the direct-sown culture. Tillers appearing from a main stem are named 1st-order tillers, those from a 1st-order tiller are named 2nd-order tillers, and so on. A node on main stem and certain nodes on tillers bear mutually a corresponding relation regarding their loci. When the 1st tiller appears, from the 2nd node on main stem (node 2), the node 2 has no corresponding node. Corresponding relations of upper nodes on main stem with nodes on 1st-order tillers are: Node 3 (3rd node on main stem) with 1 node, 2p (the 1st or prophyl node on the tiller from node 2); node 4 with 2 nodes, 22 and 3p; node 5 with 3 nodes, 23, 32 and 4p; node 6 with 4 nodes, 24, 33, 42 and 5p; node 7 with 5 nodes, 25, 34, 43, 52 and 6p; and so on. WhenY=number of corresponding nodes on tillers, n=the node number of a given node on main stem, n'=number of nodes from 1st node to n-node, and loman figure I shows 1st-order tillers, then YnI is n'-2 in this case. In a case where the 1st tiller is from the 3rd node on main stem, YnI is n'-3; and in a case where the 1st tiller is from the 4th node, YnI is n'-4; and so on. So, the number of corresponding nodes on tillers is presented by a formula YnI=m, where m=n'-number of nodes from 1st node to 1st-tiller node on main stem. Corresponding relations of nodes on main stem with those on 2nd-order tillers are: When the 1st tiller appears from node 2, neither node 2 nor node 3 has corresponding node. Node 4 corresponds with 1 node, 2pp; node 5 with 3 nodes, 2p2 22p and 3pp; and node 6 with 6 nodes, 2p3, 222, 23p, 3p2, 32p and 4pp. Thus, node 7 corresponds with 10 nodes, node 8 with 15 nodes, node 9 with 21 nodes, and so on. The general formula is YnII=m(m-1)/2. Smilarly, the number of corresponding nodes on 3rd-order tillers is presented by a formula YnIII=m(m-1)(m-2)/6. Consequently, the total number of nodes on tillers of all orders corresponding with a given node on main stem is: Yn=YnI+YnII+YnIII+······or Yn=m+m(m-1)/2+m(m-1)(m-2)/6+······. Among the nodes belonging to the same group regarding corresponding relation, there is a difference in their physiological activities giving a phenomenon that new tillers from the nodes on later-order tillers as well as from those on upper tillers of the same order are apt to appear later and to be weaker. However, in spite of the fact that the prophyl node is the 1st node on a tiller, it bears in a few cases merely a comparatively weaker tiller. In the present experiment, tillers from prophyl nodes appeared rarely in the transplanted culture but none was in the direct-sown culture. The phenomenon of tillering caused by the difference of physiological activities among nodes is quite regular in the young stage of plant. [the rest omitted]

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This paper gives the outline of general morphology of the wild Japanese barnyard millet (Echinochloa crus-galli) in connection with the paddy plant. 1. The roots of the wild Japnese barnyard millet seedling are thicker in diameter than those of the rice plant. This fact is useful to distinguish the two plants in younger stage. The development of the root of the full grown plant of the former is much better than that of the latter. 2. The culms of the wild Jppanese barnyard millet are thicker in diameter than those of The rice plant, and the number of nodes above the ground in the former is from 5 to 8. Contrary to the hollowness of the culm of rice plant the culm of the wild Japanese barnyard millet is solid, and sometimes put forth tillers from the nodes above the ground. 3. The wild Japanese barnyard millet coleoptyl freqently contains anthocyan. The first foliage leaf of the rice plant is imperfect, while that of the wild Japanese barnyard millet has an almost complete blade. The seond foliage leaf of the former resembles apparently to the first foliage leaf of the latter, but the careful observation upon the shape of leaf one can distinguish the two plants. The leaf of the wild Japanese barnyard millet has no auricle and ligule, and the development of midrib is more remarkable than that of the rice plant. 4. The inflorescence of the wild Japanese barnyard millet is a panicle and has from 100 to 500 spikelets. The plants can be classified by the form of panicles to some extent but they are not always constant. 5. A spikelet of the wild Japanese barnyard millet has two flowers, one of them is a fertile fiower and the other is sterile.

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In this experiment the growth process of the wild Japanese barnyard millet "Form A" and the paddy plant "Norin No.18" was traced. 1. The growth in height of the Japanese barnyard millet "Form A" is somewhat inferior than that of the rice plant "Norin No.18" in the younger stage, but thenceforth the former developes rapidly. In general, the inferiority in early growth of the wild Japanese barnyard millet is very important from the standpoint of suppression of this weed. 2. The velocity of increasing in the number of leaves of the main culm of the wild Japanese barnyard millet "Form A" is larger than that of the rice plant "Norin No.18"; and the former is superior in the number of leaves. 3. The rate of tilling of the wild Japanese barnyard millet "Form A" is somewhat larger than that of the paddy plant "Norin No.18", but the tillers of the latter are rather larger in number than those of the former. 4. The total number of leaves of an individual plant in younger stages increases very slowly in both the species, but thenceforth the number increases rapidly. The total number of leaves of one wild Japanese barnyard millet "Form A" is larger than that of the rice plant "Norin No.18".

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Summer weeds in the rice-field of Tochigi-Ken (districts) generally surveyed in 1949. In this districts summer weed was found to have 70 kinds of weeds. The results of researches are summarized as follows; [table]

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It was apparent that change of the leaf-length was largest at the third leaf from the last leaf of main stem, when the deficiency element (nitrogen, phosphoric acid or potassium) in the soil was kept for all the stages after rice-planting.

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1. As one of the series of the writer's reports concerning the yielding efficiency of Japanese rice varieties, the data on the length of stem of paddy rice plants in Japan are reported. 2. In all the agronomic varieties of the paddy rice of Japan studied, the minimum of stem length is 44 cm, and thg maximum 140 cm, the mode being 92 cm, the mean 91.21 cm, and the σ 10.49 cm. The distribution is a very typical monomodal symmetric curve. 3. The distribution curve of the stem length of rice varieties in each prefecture presents a typical monomodal symmetric one. The minimum of the mean is 80 cm in Akita, 81 cm in Aomori, 82 cm in Fukusima, etc. The maximum is 100 cm in Gumma, 98 om in Nara, 96 cm in Yamagata, etc. 4. A close negative correlations were found between the stem length and number of stems per tubo, the days from seeding to heading, and the latitude coefficient etc., while a close positive correlations were made clear betwen the stem length and the yield per tan, prefectural average yield per tan, and the mean temperature, etc. 5. From 1931 to 1940, a diminution of the stem length occurred according to the straightline drawn by means of R=-0.6114y+97.49 cm. 6. The positive yearly correlations were found in each prefectures between the stem length and yield per tan, - the mean temperature from April to November, - the mean temperature of July. Negative correlation were made clear betwen the stem length and the heading date, the number of stems, the amount of rain fall from April to November, and the sun shine from April to November. 7. The number of stems shows a closer correlation with the yield, than that between the length of stems with the same, if considered by the usual correlation coefficient. But the stem length shows a closer correlation with the yield, when considered from the least square equation of the yearly tendency. 8. Sembon-asahi and Norin no.1, showing the mean stem lengths 73 cm and 79 cm respectively, are the representative short stem varieties, while Watarifune and Kokuryomiyako, the mean stem length of which are 102 cm and 104 cm respectively, are the standard long stem varieties. 9. By the "deviation from the mean method" which I proposed in order to present the relative value of a given variety compared to the mean value of the population of the varieties concerned, the "deviation from the mean value" of each variety is calculated. The values are as follows. Sembon-asahi - 17.0 cm, Norin no.1 -13.3 cm etc. (shorter varieties) Watarifune +7.0 cm, Kokuryomiyako +12.3 cm etc. (longer varieties). The tendency "deviation from the mean method" coincide with the tendency of absolute numbers. 10. We can calculate the theoretical length of the stem of any variety at any locality by adding or substituting the "deviation from the mean value" from the local stem length. 11. Among the varieties of rice plants, the correlations betwen the stem length and the yield per tan, the number of head per plant, and the number of head per tubo are negative and significant, while the correlation between the absolute stem length and the "deviation from the mean value" of the stem length is positive and distinct.

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The results obtained from the study of transparency of glutinous hulled grains and the relation of the transparency to the other characters of grains for bred 12 lines of upland rice at the Odate Agricultural Improvement Experiment Station of Ministry of Agriculture and Forestry were as follows (See Table 1∼4). 1. Each individual of the lines bore the semi-transparent grains as well as the opaque grains, and the rate of coexistence of the opaque and semi-transparent grains in an ear varied with the lines. 2. The weight of opaque grains for 8 lines were heavier than that of semi-transparent grains, but the weight of opaque grains for the other 4 lines were equal to that of semi-transparent grains. On the other hand any relation could not be found between the rate of coexistence of two sorts of grains for each line and the weight difference of two sorts of grains consisting in each line. 3. The length and width of the opaque grains were bigger than that of the semi-transparent grains. But the thickness and the length, the thickness factor of the opaque grains were smaller than those of the semi-transparent grains. While the length, the width factor of two sorts of grains did not show any relation to the above mentioned transparency. 4. The specific gravity of the opaque grains was greater than that of the semi-transparent grains and the specific gravity varied with me lines. 5. The opaque grains had an inclination to be dyed deeply by the iodine potassium iodide solution as compared with the semi-transparent grains, but two sorts of grains of Tohoku-mochi No.1 had an equal degree of dyeing. Generally speaking, the ability to be dyed varied slightly with the lines.

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Some farmers to dry the glutinous rice grains pile the unhulled rice grains dried in the sun, while they are warm and cover them with straw-mats, then dry them again in the next morning. Thereupon, this experiment was studied on the effects of the temperature upon the drying of unhulled rice grains. The results are briefly summarized as follows; 1. According to the research performed at the end of October, the temperature of the unhulled grains dried until 4∼5 P. M. was 5.5∼7.5 °C in the evening, and 6.5∼7 °C in the next morning, while that of grains piled at 1∼2 P. M. and was covered by straw-mats was 25∼29 °C in the evening and 15∼17 °C in the next morning. When they were dried again in the sun, the latter grains were dried more quickly than the former grains. 2. When the unhulled grains were kept in the thermostat regulated 23 °C during the night, the water content of the unhulled grains did not decrease remarkably, while the water content of the hulled grains (kernels) decreased, and that of the hulls increased. When the unhulled grains were kept in the normal temperature, the water content of the kernels did not decrease and the hulls were kept dry. (Generally, the water content of kernels is higher than that of hulls under normal condition.) 3. Therefore, under the high temperature, water in kernels will remove into the hulls, and this will be the reason why the high temperature of unhulled grains during the night is more favourable to be dried than the low temperature. 4. These facts above mentioned will be due to the function of hull (protective organ), therefore these facts can not be found in hulled grains (kernels).

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In the preceding paper the author reported preliminarily on the effect of continuous submergence upon the growth and structure of rice plants. In the present studies, he intends further to ascertain the influence of continuous submergence on the growth of rice with special reference to its tillering. The plan and the methods of investigation are, therefore similar to those of the previous year. The variety used is Norin-ichigo, an early lowland rice. The submerged plot: The water level of 8 cm high is kept continuously since 2 weeks after seeding till harvest. The no-submerged plot: Soil is always moist enough with no submergence. The tendencies being recognized through the results of both studies are summarized as follows. (1) In Kanto District, the temperature of May (when the rice is seeded) is rather low, hence the submergence of water raises the temperature of earth and water surrounding rice plants, especially at night, because of its high specific heat, and promotes the growth of rice and advances the date of heading several days. But later in June, the temperature rises fairly high, and the submergence is not so effective as in May, but becomes rather infavourable for growth of rice chiefly due to want of aeration. Therefore, the plants seeded and submerged later in June are reduced in growth and the date of heading is not promoted. (2) In the submerged plot, the number of tillers is increased in May seeded Plants and decreased in June seeded ones, and the lowest tillering locus on the main stem is always moved upwards by submergence. (3) The culm and panicle length seems to become less variable by submergence, but the grains per plant or per head may diminish in number, the reason of which is to be studied later. (4) The form of tillering curve in rice may be analogous with that of the autocatalytic one, and each tillering curve of the first, second and third (and rarely forth) orders is its formative stuff.

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We have investigated on the growth and yield of soybean plants which were treated with deficient supply of soil moisture during 15 days at different growing stage and obtained the following results. (1) 1st series plants (treated during l5 days-period after the date of flower-bud differention) Vegetative growth was prevented. Many flowers were dropped, resulting few pods obtained as compared with the control plant. The average weight of one seed was light and this series showed the poorest yield. (2) 2nd series plants (treated during 15days-period after the date of flowering) Vegetative growth was prevented. Number of flowers was very few. Because many flowers and pods were dropped without growing to ripening, only few pods were obtained, showing the poorest yield except that of 1st series. (3) 3rd series plants (treated during 15 days-period after the date of the flowering season) They showed only few dalayed flowers and the dropping of pods were fewer than the 1st and 2nd series. Yield was greater than that of 1st and 2nd series. But it must be mentioned that they have the highest percentage of abortive seeds of all experiment series. (4) 4th series plants (treated during 15 days-period in the process of ripening) Vegetative growth and ripening process of the plants was similar to that of control plant, but the average weight of one seed was lightest of all. (5) In every series, with regard to the buds which were formed until July 20, no dropping was observed. (6) In every series, it was observed that the 1st peak of seasonal dropping of flowers took place at the same time as the formation of pods had increased to some extent, and it was also seen in 1st and 2nd series that the flowers were dropped severely when the soil moisture was increased suddenly to 70%, after the drought treatment period had finished. (7) It was recognized that when the pods grows to some definite extent, they are very easy to drop, and that growth extent scale is not differ between these five series. (8) These results may be explained as the direct effect of deficient soil moisture content on the fertility of soybean plants, but further the disturbance of nutrition which might be occurred accompanied with the insufficient supply of soil moisture should undertake a great deal to determine the fertility of soybean plants.

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The authors have observed the chromosome number of Mexican Tea (Chenopodium ambrosioides L.) and American Wormseed (Chenopodium ambrosioides L. var. anthelminticum A. GRAY), together with some other species of Chenopodium, and have studied on their cultivation, distillation, content of ascaridole, and morphology. Results obtained are summarized as follows:- 1. The authors have determined for the first time that the chromosome number of Mexican Tea is n=8, 16, and 24, and that of American Wormseed is n=32. 2. Diploid (n=8), hexaploid (n=16), and hexaploid (n=24) plant of Mexican Tea and American Wormseed (n=32) have morphologically each different characteristic features. 3. Chromosome number of some other species of Chenopodium observed by the authors is shown in Table 3, and it has been shown for the first time that their basic number is 8. 4. Ascaridole content in the essential oil of Mexican Tea was 20∼60%. Thus, it has been shown for the first time that Mexican Tea contains ascaridole. Some lines of Mexican Tea have higher yield of grass and higher content of essential oil or ascaridole rather than American Wormseed. 5. No relation between chromosome number and content of essential oil or ascaridole was observed.

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In cultivation of soybean "Ou No.13", under the same condition of external environment and different ones of seed-weight which may relatively be called internal environment, the effects of seed-weight on growth and ecological form of the plants are generally very little. But the yields are as follows; [table] It means that the cultivation using selected grains of larger weight yields more 2.61 To per Tan and grains of more volume, fat and starch than no selected. It may be that the "Ou No.13" has been cultivated so long that the stability of the variety has changed worse and the result of group selection practice proved effective.

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This investigation has been undertaken to learn the influence of temperature on the germination of rye seeds. According to this investigtion the minimum, optimum and maximum temperature for the germination of rye seeds are as follows: [table]

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The effect of night temperature upon the development of some crop plants was observed, taking wheat, barley, rye, pea and french bean as test object. Each plants which sowned at suitable season were adequately managed. Those plants were cultured to the date of harvest in two green houses, the one being heated during night time to raise the night temperature average 4°C. higher than the other (control) (Fig. I). The plants in both green houses were investigated with regard to the growth rate, flowering and fruiting habit; Some of the interesting observations are recorded here. 1). Effect upon the growth rate: Warm night, generally, were promoted the growth of the plants, but could not give influence to the leaf number (Tab. 1). French bean, however, were slower in opposition by warm night (Fig. 5). The growth of ovary of pea were promoted by warm night. (Fig. 4). 2). Effect upon the heading and flowering: The heading of wheat, rye and barley were promoted by warm night; the promotion of wheat were one month's duration, but other plants were seven to ten days (Fig.2). The flowering of pea var. AOTURUNASI were promoted by warm night, but var. KINUSAYA were delayed (Fig. 3). The flowering of red-flower french bean were clearly by warm night, or the flowering percentage was 40%, but at warm night was 0.29% (Tab. 4). And observed that the developments of pollen mother cell were retarded by warm night temperature (Fig. 6). 3). Effect upon the harvested materials: Some investigation of the harvested materials were operated only about wheat, barley, and rye. Those plants, generally, at warm night were retarded the organization of the spiklet; grain number, size of spiklet, etc., but the grains were clearly substantial (Tab. 1 & 2).

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1. This experiment was made to determine of the influence of water depth upon the growth of tillering primordium and tillering bud of rice seedlings. 2. The degrees of water depth used were three, 0 cm (saturated condition in the soil) 3.0 cm and 5.0 cm. 3. The first tillering primordium grew to about 0.5∼0.8 mm in length and 0.3∼0.4 mm in width, but after then it stopped to grow. It was rare to grow to more than 1.0 mm. However, at 0 cm, the growth was good and at 3.0 cm and 5.0 cm they become bad respectively. 4. The second tillering primordium and tillering bud received a great influence in its growth by the water depth, and it was best at 0 cm and flooded condition of 5.0 cm showed the marked inhibition of growth. There are two developments to the second tillering primordium, one which grows and appears outside of the leaf-sheath and one whose growth stops. It is judged that this variation comes from the adaptation or the non-adaptation of cultural environments. 5. In the third tillering primordium and tillering bud, up to the time of the appearing of the 4 th or 5 th main leaf the growth is most prominently at 0 cm and bad at 5.0 cm. At the appearance of the 6 th or 7 th main leaf the tendency of gradual decrease was observed between the different water depth. However at water depth of 5.0 cm some of which stop to grow. 6. In the fourth and fifth tillering primordium and tillering bud, the influence of water depth was not observed too much during the appearance of the 5 th or 6 th main leaf, but at the appearance of the 7 th or 8 th main leaf the tendency of improved growth was observed in the 3.0 cm and 5.0 cm when compared to 0 cm. 7. As to the width of the tillering primordium and tillering bud, we recognized the tendency that they grow in proportion to the length, but more slowly than the length.

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1. This report is one of the series of the writer's reports concerning "The yielding efficiency of Japanese rice variety" and the writer will relate here on the yield per tan of paddy rice varieties in Japan, andthe average yield per tan of each prefectures. 2. 43192 agronomic varieties of paddy rice of Japan are investigated. The minimum of yield per tan is 0.1 koku, and the maximum 4.5 koku, the mode being 2.70 koku, the mean 2.6088 koku, and σ 0.535 koku. The distribution is of a very typical monomodal asymmetrie curve, the center of the gravity of the curve inclines to the right a little, and the skewness is -17.3%. 3. The distribution curves of the yield per tan of rice varieties in every prefecture presents a typical monomodal asymmetric curves, and the centers of gravity inclines to the right a little. The minimum of the mean of the curves are 2.093 koku in Kochi, 2.110 koku in Tochigi, 2.196 koku in Tokyo, etc. The maximum of the mean of the curves are 3.43 koku in Yamagata, 3.177 koku in Ehime, 3.069 koku in Nagano, etc. These numbers are calculated by the means of about a thousand varieties. And these numbers may be estimated as the yielding efficiency of the respective localities. 4. For the cause of the difference of yielding efficiency in different locality, the geological difference must be most responsible. Generally speaking, the Kuroboku soil (volcanic origin, acidic humus soil) regions are small yielding, but as I could not gather the geological indexes, I report here only on the correlations between the yield per tan and the rice plant charactors and the correlations between the yield per tan and the climatic conditions. The charactors which show positive correlations with yield per tan are the stem length, the number of stem per plants, the number of stem per tubo, the average yield per tan of the prefecture, the vigorocity index I (stem length × number of stems per tubo), the vigorocity index II (stem length × number of stems per plants) the daily temperature fluctuation, the percentage of sun shine, and the latitudinal coefficient. The charactors which show almost no correlation with yield per tan are the accumulated temperature from seeding to heading, the date of heading. The charactors which show negative correlation with yield per tan are the number of days from seeding to heading, the amount of rain-fall. 5. From 1931 to 1940 the increase of the yield per tan occurred according to the straight line drawn by means of R=+0.0248t + 2.374 koku The increase of the yield per tan of the whole country occurred according to the straight line drawn by means of R=+0.0246t + 1.760 koku During these years the heading date shows no difference, the stem length diminishes (according to R = -0.611t + 97.49cm) and the number of stem per plant increases (accordingto R = +0.193t + 12.93 hon 6. The yearly correlation coefficient between the yield per tan of each prefecture and the heading date shows an interesting result. In Tohoku province, e. i. Aomori, Iwate, Akita, etc. the coefficients are distinctly negative, and in Tokai-Kinki regions, e. i. Aichi, Shiga, Kyoto etc. these are distinctly positive. The correlations between the yield per tan and the stem length are generally positive, and that between the yield per tan and the number of stem per plant are generally positive. The correlations between the yield per tan of the experiment station and the average yield per tan of prefectures are distinctly positive except one prefecture Yamaguchi. The correlations between yield per tan and the mean temperature in April-November are generaly positive and distinct, but in the West-Southern region the correlations are uncertain. The correlations of yield per tan with the mean temperature of July, and also with the percent of sun shine are generally positive. And the correlations between the yield per tan and the amount of rain fall are generally negative. [the rest omitted]

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1. The author inspected the cold water resistance of the remarkable rice varieties and lines in the Tohoku-district by flowing cold water irrigation in their principal growth period. 2. Varietal dfferences in the injury caused by the cold water cultivation in paddy field are very obvious. 3. Sterility percentages are fit to indicate the cold water resistability, as Dr. Y. KONDO insisted in his report. From result of my study, it appears that: (1) The cold water resistabilities of glutinous varieties are obviously higher than the non-glutinous ones. (2) Varieties, awned or carrying pigment with their cod, respectively are generally more resistant in comparison with reverse characteristic ones. (3) Moreover, the result indicates that high resistant varieties are more recognized in heavy-ear possessing and early maturing ones than much-sprouting and late maturing ones. 4. But I revealed that it was not difficult to rear cold water high resistant varieties which were non-glutinous, awnless and non-pigment in their cods by means of hybridization.

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In the wheat, the development of seedlings at the time of endosperm exhaustion is the growth stage of the 3 rd foliage leaf and 5.9 roots, in the naked barley, the 2 nd foliage leaf and 4.6 roots, and in the hulled barley, the 2 nd foliage leaf and 5.8 roots, at the mean soil temperature of 14.8°C. 2. The consumption curves of the stored foods in seeds and the growth curves of seedlings are represented by application of the ROBERTSON'S formula log x/(A-x) = K(t-t₁). 3. The inflection points in the curves of the top dry weights appear 1∼3 days later than those in the curves of the stored foods dry weights. 4. The stored foods in the hulled barley were consumed more rapidly in the middle period than those in the other plants. This, with the slowness of the consumption in the early period, may represent the speciality of germination in the hulled barley.

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1. Using the two-rowed spring variety "Moravia", the mechanism of sterility occurring every year with relatively high percentage in spring sown barley in Hokkaido was studied with special reference to the abnormalities of pollen, anther dehiscence, pollen shedding, elongation of pollen tube, and ovule. Then the percentage of sterility was classified according to the above mentioned causes. 2. The greatest cause in the sterility was non-pollination due to the abnormalities of anther dehiscence and pollen shedding by its wettish condition at the dehiscing time, and this cause took place about 60% in the total percentage of sterility. 3. The sterility due to the abnormalities of pollen and pollen tube (the latter involves the following phenomena: 1. upward, not downward, elongation in stigma, 2. abnormal swelling in the tip of pollen tube in stigma.) took place respectively 1O% and 1% and the non-germination of pollen on the stigma did about 20% in the total percentage of sterility. 4. Female sterility due to the abnormality of embryo was only 10%. Accordingly the sterility in barley belongs to the male sterile (cf. Table 9).

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In 1949 experiments were performed in order to explain the relation between the characteristic properties of the underground parts of paddy rice plants and the comparative varietal drought resistance, using the same materials and methods as those of the primary report. The results are summarized as follows: 1. Almost pararell relation was recognized between drought resistance and following characters of root system; root number, sum total of root length, depth and distribution of roots in underground section. (Cf. Table 1) 2. Same results were recogniged as to the new produced root profil except the root number. (Cf. Table 2) 3. In the 3rd observation, drought resistance was more or less related with the length of the longest root in a stock, but scarecely with the other root characters. (Cf. Table 3) 4. It was proved that in the case of supplication of silicic acid the root system developed vigorously and the dry weight of roots under a stock conspicuously increased. (Cf. Table 3 & plate 1.)

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At the 83 rd meeting of the Crop Science Association (1949), we reported already the first result on the effect of the opening time of irrigation about the growing and yield of the transplanting rice. This time we have studied on the above-mentioned subject applying the method of direct sowing and transplanting. Among them we are now going to report on the growing of root investigated by the washing method. (1) In comparing of direct sowing with the transplanting, the former is superior to the later in the growing of top and root. (2) In the direct sowing, we could not find any difference in the dry matter between the division filled with water from the beginning and the one filled just before the head forming, but in the transplanting it was found the division filled with water from the beginning was the best than the others. (3) In the transplanting division, the section filled with water on the 26 th of July was heavier in the dry matter of root than that filled with water on the 16 th of the same month.

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The material used in this investigation is the root nodules of soy bean, which were fixed in Bouin's solution and stained in Haidenhain's iron-alum-haematoxylin. Sections were cut at 7-10μ. According to this investigation, amitosis have been observed during the early development of the bacteroid tissue. At the beginning of the amitosis, there appears small chromatin granule at one point of the nucleolus (Fig. I). And secondary nucleolus is gradually developed from the chromatin granule separating from the original one (Figs. 2, 3 and 4). At about the same time, the nucleus becomes somewhat oval in shape (Fig. 4), and later, a constriction appears in the centre of those two nucleoli (Figs. 5 and 6) to separate them into two daughter nuclei (Fig. 7). MILOVIDOV (1926) has distinguished following three types of root nodules with respect to the mode of infection. (a) Normal type : infection takes place by aid of intracellular infection threads. (b) Type in Serradella : Infection takes place by aid of intercellular infection threads. (c) Type in Lupinus : Infection takes place by aid of mitotic cell divisions. It is desirable for me to add one more type, namely, type in soy bean in which infection takes place by aid of amitotic cell divisions.

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The root nodules of lupine have a number of separated bacteroid tissue with a varying amount of non-infected tissue between them. Very often, infected threads are prominent in the young nodules. The leguminous nodules can be placed in four groups with respect to the mode of infection of the bacteroid tissue. 1. Infection is produced by aid of infection threads. a) By intracellular threads. For example, Broad bean. b) By intercellular threads. For example, Serradella. 2. Infection is extended by aid of cell divisions. c) By mitotic cell divisions. For example, Lupine. d) By amitotic cell divisions. For example, Soy bean.

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The flood in the early period of growth, as it is high in temperature, is apt to do much damage to the vegetable organ, but has comparatively little effect on the harvest. But after the period of legume, considerable harm was witnessed in the mechanism. This harm was considerable in the stage of legume, less in that of the completion of the outer size, and the least in the ripening stage. Contray to my expectatioh, the harm in the flowering period was very few. This experiment was made in the natural environment and water temperature was not regulated, because the following hacts were taken into consideration that with the growth of the autumnal soybean there was a change in season and that water temperature changes with it.

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In broad bean, the nodule bacteria of roots enter the host plants through their root hairs and remain rod-shaped during the early period of infection. But, with the development of the nodules, the bacteria assume a characteristic form, e. g. T, V or Y shape, which are known as bacteroids. Hence, in the nodule bacteria of roots, we can recognize following two forms. 1. Moving form : Rod-shaped. 2. Settling form : Known as bacteroid, mostly T, V or Y shape. The transformation of nodule bacteria from the moving form to the settling one seems to be connected with the nitrogen fixation which is performed by the bacteria. Perhaps, the transformation may occur to facilitate the function of nitrogen fxation. In some species such as soy bean, the bacteria do not assume the transformation during the nitrogen fixation. But, they are also desirable to call the non-transformed bacteria as bacteroids. Because, bacteroids do not mean the bacteria transformed but the one settled for nitrogen fixation.

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1. The greater part of leaves of 6 varieties among 265 varieties of soybean plant preserved at the Odate Agricultural Improvement Experiment Station of Ministry of Agriculture and Forestry did not fall off even in autumn. 2. It is considered that the non-leaf-fall varieties originated in U.S.A. 3. Through surveying the duration from seeding to flowering and the length of the growing season, I saw that the non-leaf-fall varieties were admitted into the medium and late varieties except one very early Chestnut. 4. The starch was almost entirely absent in the seed and in the main pulvinus at the yellowish leaf stage of non-leaf-fall varieties. But the starch was not found completely in the grain of the other non-leaf-fall varieties. 5. The weight of gains of non-leaf-fall varieties was more light than that of any other varieties in general. 6. The seed coat and the hilum of gains of the non-leaf-fall varieties put on a dark colour.

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This paper is a preliminary report of tripping experiments ot alfalfa (Medicago sativa) flowers. The staminal column and stigma of this flower were anatomically studied and the results obtained are as follows: In the transverse section of the staminal tube, the lower part of this organ is thicker than the upper part in width and the cell size of the former is larger than that of the latter. In the longitudinal section, the external cells of the staminal column are thicker in width and longer in length than those of the inner cells. Cuticule-like membranes were found on the stigmatic surface and granular fatty substances were secreted in the space between the stigma projection and the stigmatic membrane. However the structure of the stigma remarkably differs from what JOST has found on the stigma of Cytisus and Lupinus. The turgor pressure at the outer tissue of the staminal tube was higher 1.1 atmospheric pressure than that of the inner tissue. The motive power of tripping exists in the staminal column but not in the pistil. The pod setting of alfalfa was increased remarkably by artificial tripping compared with that of non-treatment, but when the standard petal was removed and tripped artificialy the fertilization of this plant was almost same to the case of non-treatment. The authors consider that the scope of tripping on the increased seed setting is in the confliction of stigma and standard petal. It is a problem to investigate minutely in future that the confiction of those organs produce results to either the scattering of pollen, the destruction of the stigmatic membrane or the both.

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Using the soil of the farm, the amount of the three manurial elements contained in the soil and the effects of them upon the growth of MURASAKIOMOTO (Rhoeo discolor HANCE), were investigated, by providing five plots, containing three elements (NPK), without nitrogen (PK), without phosphorus (NK), without potassium (NP) and no element (O). Results obtained are summarized as follows. 1. In NPK and NP, the growth of the plant resembles much to each other and hardly no difference was recognized; in PK and O, the growth of the plant also resembles to each other, but generally that in O is inferior somewhat to that in PK; in NK, the growth of the plant is worst among all plots. Consequently the soil used in this experiment seems to be short of nitrogen and phosphorus, and contains a tolerable amount of potassium. 2. In PK and O, the length of the leaves and the height of the plants are smaller than those in NPK and NP, but proportions of the breadth and the thickness of leaves, to the length of them are larger than those in NPK and NP; the development of water-tissues is remarkable, therefore the water content and the raw weight of leaves become larger comparatively, but the contents of dry matter and water-extract become much smaller than those in other plots; leaves are lighter in the colour of assimilation tissues and pigment tissues than in that of others; the development of reproductive organs and tillers is inferior to that in NPK and NP; the development ot roots is conspicuously better, namely the weight and the maximum length of roots are much larger than those in others. 3. In NK, the number of dead leaves is somewhat larger than that in other plots, and the number of live leaves and the length, breadth, and thickness of leaves are smallest among all plots, consequently the height of the plants and the weight of raw leaves become smallest, too; the colour of assimilation tissues and pigment tissues was recognized to be tinged slightly darker; a tendency of a very poor develepment of the main stem, reproductive organs and tillers was recognized ; the development of roots is worst, namely, the weight and the maximum length of roots are smallest.

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1. For the study on the cultivation of Kuzu, especially the fundamental study of its increase, form and power of wild seeds were investigated first. 2. Between the legume length and seeds which were embraced in one legume, the correlation ratio was found 0.881±0.005, but its good seeds were very few, (24.3%), even the legume which was grown completely. For instance, the means of flat legume were 55.12±0.406 mm in length, 7.80±0.021 mm in width. 3. The seed was reniform, navel was round and white, and navel seam was clearness, but the location of micropyle and radicle was indistinct from outside. It had water as the ratio 13.39%, weight of a thousand seeds was 12.441 g and its specific gravity was 1.106. 4. As the result of germinating examination, the ratio of energy and hard seeds was each 10% and 50∼60%. It will be the most effective method for that the hard seed is removed, to hurt the seed coat. If the hard seed is removed perfectly, its germinating energy will rise about 90%. On the method that the hard seed is soakd in sulphuric acid, its germinating power rises, but when its soaked short time, this method shows scanty effect for that the hard seed is removed.

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In this experiment, the Norin No.32 was used as a test rice plant. By doing BAIDO during the growing period of rice-plant, the growth of them was injured. Those compensations of the test rice plants that appeared in consequence of BAIDO were as follows; 1. In the case BAIDO was done comparatively earlier, for example at the A section that BAIDO was done on July 4, the tillers in the early period of growth of rice plants were injured. Compared with the no treatment section (the D section), the tillers and their effectuation temporarily decreased at the treatment section. But afterwards the tillers were promoted, and the tiller's number and their effectuation were increased. Especially the nods that grew some time after the injure remarkably compensated. 2. At the C section, BAIDO was done on July 20 and it was directly before the stage of premodial panicle development. So, the compensation that effectuated the culms tillered lately was recognized. But the compensation for the culms tillered early was rather chief and powerful. 3. At the E section, BAIDO was done on August 4 and it was already at stage of premodial panicle development. So the injure was powerful. And compared with the A and C section, the range of compensations was narrow. The compensation increased only the ear's weight of the culms tillered in the middle period of growth of rice-plant.

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Studies on the germination of seeds of "Nori-Asa" (glutinous hemp), an amphidiploid crop raised between Abelmoschus esculentus and Abel. Manihot, which were stored in different conditions were made, in comparison with those of the parents. In the first year after storing seeds, there was no difference in each crop between the germination of seeds stored in the normal condition and in the dry state. In the second year, the germination of seeds stored in the normal condition was similar to that in the first year, but that of seeds stored in the dry state was poor. The degree of poorness was the largest in "Nori-Asa", medium in esculentus and the smallest in Manihot. But, the germination of seeds of each crop stored in the dry state was similar to that in the normal condition, if the seed coat was mechanically injured. So that, the cause of the poor germination of seeds above cited is in the difficulty in absorbing water due mainly to the mechanical change of seed coat brought about by the dehydration. The water content of seeds stored in both conditions was the largest in "Nori-Asa". The size and weight of seeds of each crop stored in the normal condition were somewhat larger than those in the dry state, the decrease of weight in the dry state being most prominent in "Nori-Asa". The water absorbing ability of seeds of Manihot was the largest, no difference being found between both conditions, but those of esculentus and "Nori-Asa" stored in the normal condition were quite larger than those stored in the dry state. The light line which may play some important roles in the absorption of water and consequently in the germination of seeds is found in the seed coat in esculentus and "Nori-Asa", but not in Manihot. The inner half of palisade tissue in the seed coat of "Nori-Asa", whose cell membrane was consisted of lignin, was thicker than those of esculentus and Manihot. The amount of respiration of seeds stored in the dry state was the same in three crops, but that in the normal condition was the smallest in Manihot. The amount of peroxidase of seeds stored in both conditions was the largest in "Nori-Asa".

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Measuring the weight of the dry matter of leaves at various periods of growth, the cabon assimilation, the translocation of assimilates and the eespiration in the leaves of "Nori-Asa" (glutinous hemp). an amphidiploid crop raised between Abelmoschus esculentus and Abel. Manihot, were studied in comparison with those of the parents. The absolute weight of the dry matter in the leaves located at the upper and middle parts of the stem of "Nori-Asa" was smaller than those of the parents at the middle of July, but at the end of August, it was smaller in the latters than in the former. In each crop, the increase of the dry matter of leaves began at 6 a.m., and it continued in "Nori-Asa" and esculentus to 6 p.m., but in Manihot to 3 p.m., The maximum increase of the dry matter of leaves in each crop was met with at from 9 am to noon. The amount of the increase of the dry matter of leaves in the day time and also in a whole day was the largest in "Nori-Asa", and that in esculentus was larger than that in Manihot, except at the middle of July. On the translocation of assimilates and the respiration in the day time, in the night as well as in the whole day, no difference was found among each crop. The amount of carbon assimilation was found to be the largest in "Nori-Asa" at every period.

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On the culture of the rice plant in the northern region, it is usually required to accelerate the growth and ripeness of the rice plant in some way, and to gain the stable yield of the crop. From this point of view, we have studied for these 3 years about the effects of the double treatment of the high temperature vernalization and the short day treatment for rice species, using an electric hot seed-bed. The result (1949) follows: Some species were accelerated the growth and ripeness in paddy-fields by the 10 days high temperature (25∼35°C) and the succeeding 15 days short day (8 or 10 hrs. day) treatment in the period of nursery seedling, and tbeir yields of rice were increased by about 10%. We think this method is simple and it will be able to be applied practically for the rice culture.

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It has already been reported that oxygen requitement of crop roots in the soil varied with the difference of crops or varieties. The author found a close relation between reducing power and oxygen requirement of roots during the water-culture of various plants, and then cultured young plants in a solution containing nitrate as nitrogen source (cf. table I) and investigated the amount of nitrous acid formed in the solution. Soybean (12 varieties), barley (14 varieties), wheat (7 varieties), sweet potato (12 varieties), rape (14 varieties), other two or three crops and weeds were employed in this experiments. All these plants excluding sweet potato were sown in the quartz sands until they bears one or two leaves, then the seedlings were water-cultured in the 300cc flasks covered by blackpapers, and the plants were supported with cotton stoppers. On sweet potato, the top of vine was cut in 15 cm and then water-cultured. The solution was changed every 3-4 days and nitrous acid in the residual solution was measured, and the total amount of nitrous acid formed during the term of water-culture (generally one month) was calculated. The results of the experiments are as follows : Nitrous acid was not formed in the culture solutions of paddy rice, Alopeculus aequalis, and Beckmannia erucaeformis, but it was found in those of barley, wheat, soybean, corn and rape having strong reducing power in their roots (cf. table 2). Considering from these facts upland plants generally have the strong reducing power of nitrate in the culture solution, but marsh plants have the very weak reducing power. Further the varietal difference of nitrate reducing power was investigated with soybean, sweet potato, barley, wheat and rape, and the following results were obtained (cf. table 3-6): Drought-resistant varieties form more nitrous acid than drought-susceptible varieties in the same species, but dump-resistant varieties form less nitrous acid on the contrary, i. e., have less reducing power, than the susceptible varieties. According to the results, it may certainly be concluded that the reducing power is closely correlated with oxygen requirement in roots, i. e., species or varieties having the stronger reducing power in their roots require more oxygen in the soil.

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The questions of photoperiodism and light inhibition have provoked much discussion among physiologists. In order to dispose of these vexed problem of long standing, we must grasp firmly the conception of light effects. In this paper we made an effort to treat this tangled question from an entirely new angle, and to investigate the phenomena from the electro-physiological side. The results obtained were the following: 1. Studying the light effects upon actinomyces it was found that the specific effects cf wave length were obtained at different intensities. 2. Irradiation with short wave light caused negative electromotivo force while red light produced the potential change of opposite sign. With regard to the so-called excitement, the blue light has the most sensitive property. 3. As seen from figures presented above, actinomyces showed also significant responses after cessation of red light at low intensities of light. The color reactions are not independent, but exert some influence on each other. 4. We found that this off-effects were produced by release from counter-action motivated by long and short wave light with varying its intensities. This finding may be valuable contribution the crop physiology. 5. Analogous phenomena were observed among several plants. Which may probably conceal some of multiple excitements. Such complex phenomena of light inhibition in the crop may be also interpreted in terms of certain interaction taking place in the tissues stimulated by light. From our results we could enter upon the theoretical phases of the problem of light stimulation. As yet we have done no more than touch this subject.

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Since the author (1929) found that the resistance of the toxic action of KClO₃ correlated positively with the drought resitance in seedlings of rice varieties, the close relationships of the toxicant resistance to the other several kinds of characteristics of certain plants have feen observed by him as well as others, the results hitherto obtained being briefly summarized as follows. (1) Cold resistance: The cold resistant varieties are less resistant to the toxicant (Wheat, Barley, Rape, Genge, Radish, Brassica, Loquat and pine trees.) (2) Drought resistance: The drought resistant varieties are more resistant to the toxicant (Rice-Paddy and Upland rice-Upland rice only.) (3) Earliness in ripening: The earlier varieties are less resistant to the-toxicant than the later ones (Rice and Sugar-cane) (4) Sex: (a) The males are more resistant than the females (Hemp, Spinach Aucula Japonica and Remux Acetosa L.) (b) The males are less resistant than the females. (Papaya, Strawberry and Asparagus) (5) Double flowered and single flowered plants: Double flowered plants are more resistant than the single flowered ones. (Matthila incana and other many kinds of flower plants) (5) Virus diseased plants: Diseased plants are less resistant than healthy ones (Many kinds of vegetable crops and Tobacco plant.) (7) F₁ plants: F₁ plants are more resistant than either of their parents (Egg-plant) (8) Teratological forms: Teratological forms, especially in sexual organs, are more resistant than the normal ones (Rice) showing the materials used in the auther's experiments. Basing on the results of various kinds of tests with rice and wheat plants, the auther has ever put forward the hypothesis pertaining to the physiological cause of the toxicant resistace as is shown below: The chlorate itself is practically harmless to plants, but the salts are reduced by the reducing substances contained in plants, such as glucose, aldehydes, etc., resulting in the formation of hypochlorite which acts directly poisenous on plants and consequently the resistance to the toxicant is dependent on the amount of the substances concerned, i. e., the more the amount of the latter, the less the resistance to the toxicant. (Here, the amount of the reducing mattersiod in plants was compared by that of the ine consumed by the oxidation.) By the further study, the above-noted hypothesis is found also applicable in the case of the toxicant resistance with thesex es as well as double versus single flowering. The reducing substances, it may be believed, have much to do with the problem of the oxidation-reduction within plants. This idea is supported by estimating the activity of catalase (oxidizing agent) and the amount of the ascorbic acid (reducing agent) with rice, wheat and flower plants. From the results of the present research, it may be noticed of most importance to find out the reason why the characteristics conserned have the certain relationships with the oxidation-reduction reaction within plants for which some study along this line is now under way in the author's laboratory.

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Lodging indices, date of heading, plant height, number and weight of panicles per hill, and grain yield per unit area of eight varieties of rice were studied in individually space-planted (IS), normally transplanted (i. e. three plants per hill) (NT), and directly seeded plots (DS), each in six replications of randomized blocks (Tab.1). The F values for comparing variety and error mean square, calculated by the analysis of variance, exceeded the 1 or the 5 per cent points (Tab. 2). The correlations between the characters of rice-plants in IS and those in NT were significantly high except the weight of panicles per hill (Tab. 3). The correlation coefficients between the characters of ric-plants in IS and those in DS, however, were not significantly high except for lodging indices, date of heading and plant height. It may therefore be concluded that, while the behavior of individually spac-planted plot as a criterion of behavior in normally transplanted plot seems to be considerably reliable, the former as a criterion of behavior in the directly seeded plots seems unreliable except for lodging, date of heading and plant height. Moreover, the correlation coefficients between the grain yield of DS or NT and the number or weight of panicles per hill in IS (Tab. 4) show, in so far as my present materials are concerned, that the grain yield of varieties directly seeded or normally transplanted cannot surely be predicted from the number or weight of panicles in individually space-planted plots.

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Plants of two varieties of rice which were quite different in plant colour and yielding ability were planted in the same plots after the manner of mixing each other as shown in Fig. 1. These plots were replicated six times (Fig. 2). The width between rows was 10 inches and the plants spaced five inches apart within rows. From these plots, plants surrounded by those of the same variety (AS), plants in rows adjacent to another variety (ND), plants grown between two of another variety in 10 inches (LD) or in 5 inches apart (SD), and plants surrounded by those of another variety (AD) were individually harvested. The grain yield in grams, the number of spikes and the average weight of a panicle were recorded on plant basis in each plot (Tab. 1). The analysisses of variance were calculated from the nonweighted plant values (Tabs. 2∼4). From Tab. 2, it is seen that the mean square for varieties, and varieties x treatments, compared with error mean square, exceeded the 1% point and those for treatments the 5% point. It is plain, therefore, that there were significant differences in average yielding ability and that these varieties reacted in a differential manner at some treatments. These differential response of the varieties to some treatments was shown to result from the changes in the weight of a spike under different treatments (Tab. 4) and not the number of spikes per plant (Tab. 3). Average grain yields in Tab. 1 sbowed that those of the low-yielding variety became lower by the influence of neighboring high-yielder, and vice versa. It was concluded that the yield of spaced single plants in a population would be variably affected by the surrounding plants, and it would, therefore, be illegitimate to make plant selections on a basis of the yield of single plants in segregating generations.

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The object of the study reported in this paper was to find the proper size, shape, and number of replications of this size necessary for varietal yield trials with rice. 2. With the area constant, the standard error increased as the size of plot was increased. 3. With area in proportion to size of plots, increasing, the size of plot reduced the standard error of the single replicate, the efficiency of plots is the highest in the smallest plots, but it required several more replications than another. 4. The reduction in the standard error is rapid until about 4 th replication, when 6 th the rate of reduction decrcases markedly. 5. The results above mentioned indicate that plots 5 shaku long and 2 row wide replicated four times would be satisfactory.

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With the aim of studying the growth and the susceptibility of rice to Helminthosporium disease as influenced by aeration and the kinds of mineral elements supplied, some solution culture experiments were carried out during 1948 and 1949 at Konosu farm of National Agricultural Experiment Station. Results of experiments are summarized as follows:- (1) Regardless of the kinds of mineral elements supplied, the plants growing in unaerated solution, to which saturated solution of hydrogen sulphide was added, showed the poor growth and the high susceptibility to Helminthosporium disease as compaired with the plants under aeration. (2) The deficiency of potassium, silica, manganese or magnesium decreased the plant growth and increased the susceptibility to the disease, regardless whether culture solution was aerated or not aerated. Addition of copper and iron bad also the same influence as above induced by the deficiency of potassium or such elements. While the deficiency of nitrogen decreased slightly the susceptibility. (3) The addition of sodium sulphate to the culture solution had no effect on the susceptibility under aeration, whereas it increased the susceptibility when the solution was not aerated. Such an unfavorable effect of sodium sulphate in the unaerated solution might be attributed to the injurious effect of hydrogen sulphide produced by the reduction of sulphate ion on root growth. (4) The plant growing in unaerated solution with H₂S showed lower percentage content of potassium, manganese or silica in stem and leaves than that of the plant growing in the aerated solution. Such a low percentage content of nutrient elements in the former plant seems to be related to the retardation of absorptive function due to the root injury. (5) Supply of larger amount of H₂S resulted in the poorer growth and higher susceptibility to the disease. However such an injurious effect of H₂S was diminished by the addition of manganese.

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In view of the importance of the "uzu" or semi-brachytic habit of growth for the breeding, the cultivation as well as for the genetics of the Japanese barley, the linkage relation and the geographical distribution of the gene for this character were investigated, the summarized results of which were presented in this report. 1. It was shown that the gene pair for normal versus uzu was in herited independently of gene pairs as follows: Vv, Alal located in linkage group I, Bb in group II, Ll. Nn, Lklk in group III, Blbl in group IV, Rr, Ss, Fsfs in group V, and also Fcfc, Ycyc in group VII (the data was omitted) 2. Linkage relations between Uzuz and two gene pairs for chlorophyll denciencies, Acac and Anan, both of which had been known to be located in group VI, were shown in Table 1 and 2, and the gene arrangement on the VI chromosome in barley inferred was given in Fig.1. 3. Cultivated area of the uzu barley in Japan had been enlarged by 5.1 percent during 13 years from 1932 to 1945; it occupies 80 percent of the whole barley acreage in Japan at Present. 4. Geographical distribution of the normal and the uzu barley in Korea in 1940 were investigated, which was shown in Table 3. In spite of the fact that the uzu barley covered as large as about one third of the whole barley acreage in Korea at present, it was obviously known that this form of barley was not indigenous to this country, but had been introduced from Japan since its annexation to Japan. 5. The uzu form of barley is seldom found in the other regions except Japan and Korea. Based on the informations thus obtained, it was reasonably suspected that the uzu or semi-brachytic form of barley had originated by means of gene mutation from a certain normal variety in Japan, host probably in the southern part of it.

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I investigated the relation between the growth time and the stage of moisture, by keeping the water below the surface of the soil by 10 cm, for 20 days every 10 days immediately after sowing. The result of this experiment showed that the harm done to the growth and the harvest was remarkable in the following two stages : the period when tiny panicles appeared and 10 days after blooming, the high time of storing nourishment in the seeds, especially starch. This ill effects in mechanism resulted, in the former, in the decrease in the number of ears on one plant, and in the number of grains in one ear, and, in the latter, in the decrease in the weight of 1000 grains.

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1. Fertility of F₂ plants : - The seed setting per spikelet of the F₂ plants having 2n=42 chromosomes shows 2.4 times the fertility in percentage compared with the plants having 2n=41 chromosomes (Table 1). 2. Germination of F₃ seeds : - The seed obtained from F₂ plants having 2n=41 chromosomes shows higher percentage of germination than the seeds from that of 2n=42 cbromosomes (Table 2). 3. Chromosomes of F₃ plants : - Somatic chromosomes of 163 individuals of F₃ plants showed that they varied from 39 to 60 and their modes were 42 (Table 3). 4. Fertility of F₃ plants : - The fertile individuals having 2n=42 chromosomes in 117 fertile F₃ plants show the highest percentage with regard to the seed setting per spikelet (Table 6).

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A study has been made of the anatomical development of the embryo in wheat, barley, rye and oats from a point of view of the developmental morphology of crops. In this study, the writer has inquired, the developmental process having been detailed especially the progress of differentiation of the various parts and the change in the size and shape of the embryo at different stages from the time of anthesis or hand-pollination to the maturation of the ovule into a seed. The material used in this study consisted of 19 varieties belong to Hordeum ssativum JESS., with different growth-habits and characteristics of the plant and grains. Although, the general process of the development having been summarized only about one variety in this paper. The one variety was pollinated by hand-pollination, and the others were examined with the natural pollinated flowers. The method of preparing the material for microscopical study was as follows: Freshly harvested samples were fixed in BOUIN's or SCHAFFNER's fluid, and embedded in paraffin by the usual methods. Paraffin sections were cut at 8μ to 15μ, depending on age, and stained with double stain for erythrosin and DELAFIELD'S haematoxylin. The result of this investigation about the one variety - Ehimehadaka-1 - is summarized as follows: (1) The first cell division of the proembryos was completed about 48 hours or more after hand-pollination. (2) The differentiation between the dermatogen and the central core occurs at the stage of 4 or 5 days old after pollination. (3) The first sign of differentiation of the rudiments of each organ in the proembryos occurs 9 or 10 days after pollination. (4) About 11 days old after pollination the development of the coleoptile is seen, and the rudiment of the first foliage leaf may be seen somewhat later. (5) The rudiment of the second foliage leaf appears at the stage of 15 days old, and the third foliage leaf may be seen at the stage of 20 days old after pollination. (6) The fourth foliage leaf is the upper most leaf on the plumule of embryo in barley, and the stage of the differentiation of the leaf is from 35 days old onwards. (7) The epithelial layer of the scutellum forms its original shape about 20 days old. (8) About 20 days old after pollination all orgns of the embryo are completely differentiated, but they grow perfectly about 30 days old after pollination.

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1) Cytological observations were carried out on the triploid hybrids obtained from the cross, tetraploid Solanum tuberosum var. Irish-Cobbler × diploid S. sp. Tayama-shu (this species is assumed to be S. geniocalyx or S. stenotomum), and their parents. 2) In the species Tayama-shu, 12_II were arranged regularly in the equatorial plane at MI, and thereafter the chromosome behaviours preceeded normally. 3) In S. tuberosum L. var. Irish Cobbler 24_I were arranged regularly at the Metaphase of the heterotypic division, as these situation have been recognized also in the division of other varieties of S. tuberosum exhibiting some irregularities in meiosis. In addition to this, from one to two quadrivalents or from one to three trivalents were often met with, and in the second division the fusion of both nuclear plates occurred in high frequency, resulting the formation of corresponding number of dyads together with tetrads. 4) At the Metaphase of the heterotypic division in F₁ hybrids the chromosome configuration of (5-12)_III + (0-8)_II +(0-6)_I were observed, and the average value of tri-, bi- and uni-valent chromosomes per cell calculated from about 40 cells and their standard deviation were 8.25±1.70, 3.18±2.05, and 3.18±1.46 respectively. At the beginning of homotypic division both apindles of all cells approached nearly, fused with each other. At Metaphase, they formed a single nuclear plate, divided equationally, thus resulting the formation of dyads instead of tetrads. 5) Supposed that they have the ability of fertilization, the dyads formed by such behaviours in meiosis will make the induction of polyploidal progenies possible.

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Seed tuber in the potato plant relates very greatly in its growth and yield. Here the author observed a periodical relation of mother tuber to plant growth and tuberization. The experiments were carried out during 1947, 1948 and 1949 years. The results observed are as follows. 1. The growth of serial part (shoot and leaf weights) and the process of tuberization were observed upon the material plants used of each year. The growth curves of aerial part were expressed as Robertson's formula and the changing points of growth-rate were about the 20 th day after sprouting and the stage of the maximal development was about the 40 th day after sprouting. The process of tuberization could be distinguished in 4 periods as already reported, namely stolon elongation period, tuber formtion p., tuber enlargement p. and tuber completion p. A stage of transition from the stolon elongation p. to the tuber tormation p. began at a direct stage after the changing point of growth-rate. 2. Morphological changes of the mother tuber with plant growth were observed by 5 classified degenerating-grades. The first degeneration was seen at the stage of about the 30 th or the 35 th day after sprouting and afterthat the degeneration advanced qualitatively and quantitatively. 3. The nucellus and the cytoplasma in the cell of mother tuber were seen clearly at the stage before collape of tissue in mother tuber, but the cytoplasm was only a thin layer. A characteristic fact of the collapse was a separation of each cell. YASUI (1946) has reported that the collapse of tissue in mother tuber probably causes by an unbalance of anabolism and catabolism in the mother tuber. The first part of collapse of tissue was mostly the inside of vascullar bundle, namely outernal medulla and in this part dead reaction of the tissue was observed firstly. 4. Starch grain in the mother tuber could be scarcely seen at about the 20 th day after sprouting (Fig. 1), and various abnormal forms which probably showed degenerating processes of the starch grain were observed during the process of numerical decrease of it. 5. Dry matter and water contents of mother tuber at each stage of plant growth before the 40 th day after sprouting were observed on percentage to fresh material at every stages and the comparative value aginst seed tuber before bedding. The dry matter content decreased rapidly before about the 20 th day after sprouting and afterwards its change became very little. Change of water content expressed as percentage of fresh material was opposite to it of dry matter, but the comparative value of water content increased rapidly after sprouting to about 130% by water absorption and afterthat the value did not changed with a constant tendency. 6. Changes of main compositions expressed as percentage of fresh material were observed. The contents of total carbohydrate and total nitrogen decreased rapidly before about the 20 th or the 30 th day after sprouting and afterthat these changes were a little. The contents of total and reducing sugars increased before the 10 th day after sprouting and afterthat decreased more or less. 7. At last the author considered a periodical relation of mother tuber to plant growth and tuberization in potato plant on the ground of the observations described above. The mother tuber in potato plant relates of very great to first growth of aerial part till a stage of changing point of growth-rate and before tuber enlargement period, and afterthat the mother tuber stores water till its collapse, but the water storage is supposed to be only a phenomena with a secondary significance among roles of mother tuber.

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Previous year, the fundamental studies of the secondary growth of potato tubers, that was one of the most serious drowback in cultivation and utilization of potato in Hokkaido, were carried on by the water culture method. In this experiment now the changes of concentration of culture solution and the duration of treatment affect to the secondary growth of potato tubers were examined. In this experiment we obtained the results that the secondary growth of potato tubers was induced by the treatment of 24, 48 and 72 hours with 25 times and 24 and 48 hours with 50 times normal concentration of culture solution, but the plants which were treated 72 hours with 50 times and 24, 48 and 72 hours with 100 times normal concentration of culture solutioh were killed.

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1) In order to obtain a fundamental knowledge for the control of weeds, the writer have investigated since 1942, under the co-operation of thirty seven plant taxonomists who live in different regions of Japan, what kinds of weeds are found on the paddy field as well as the upland field and how is their geographical distribution. 2) Japan was subdivided into 10 weather sections according to Dr. FUKUI, that is Hokkaido (B.C) Sanriku (Ej), Ryou (Ep), Hokuriku (Eq), Tozan (El), Tokai (Ek), Sanin (Fr), Setonaikai (Em), Kitakyushu (En), and Nankai (Eo), and each of these districts were investigated kinds and their abundance of weeds in paddy field. 3) The total number of species of weeds grown on paddy field in the whole region of Japan, except in Hokkaido, amounted to 186 species of 42 families. Among them, 30 species were recognized as the most noxious, 68 species as the moderately noxious and 88 species as the slightly noxious. 4) Hokkaido has considerably different kinds of weeds in the paddy field from the other part of Japan; about 73 species of weeds which are distributed in Honshu are not in found in Hokkaido, and, on the other hand, some frigid plants which are not seen in the Main Land grow on the paddy field in Hokkaido. This seemed to be due to the low temperature and the short historical period of rice growing in the district. 5) Majority kinds of weeds are more or less widely distributed throughout Japan, exclusive of Hokkaido, and weeds on the paddy field which are confined to the south-western part are only 9 kinds. 6) Among 186 species of weeds on the paddy field in Japan, only a few species are endemic to this country, majority parts of them being common to the other part of the worId, and they are considered to be originated from south-eastern Asia and southern China. 7) It is noteworthy that there are very few species of naturalized weeds on the paddy field which are distributed in a limited area, while that as many as about 80 kinds of naturalized weeds on the upland field in Japan are known to have invaded from some foreign countries in recent time.

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