The auther had formaly reported on the empty husks in rice plants, aud pointed out that the sterile grains and blasted grains (fertilized but blasted in early stage to their development) are included in the empty husks, and parthenocarpic grains are found frequently in sterile grains. The present studies were carried out on the effects of restricted sunshine, of darkness and of restriction of number of flowers on panicle upon the occurrence of empty husks, in order to ascertain which stage of growth will be seriously affected dy these unfavourable conditions and to inquire into the cause of the occurrence of empty husks. The results are briefly summerized as follows : - (1) Sterile grains were numerously found on the heads which had been treated (under restricted sunshine or darkness) at the heading time or there about, to be more exact the flowers which were on these heads and opened at the latter period of treating duration were most seriously affected. Under such environmental conditions (restricted sunshine and darkness), physiological activity of rice plant became weaker and weaker, and fertilizing ability of flowers decayed gradually, though pollination has been normally performed. Under restricted sunshine, fertilizing ability of the weaker flowers such as the second and the third flowers on second order branches of panicles diminished and that of the other vigorous flowers did not diminish, but in darkness that of the vigorous flowers diminished as well as that of the weaker flowers. These may be due to the fact that the physiological activity of plant declines more badly in darkness than under restricted sunshine. (2) Blasted grains were numerously found in the weaker flowers on the heads which had been under restricted sunshine for 10 days from few days after heading, but they were rare in the other flowers on the same heads. Darkness for 4 days influenced scarcely on the occurrence of blasted grains. Under restricted sunshine, physiological activity of plants become weaker and weaker, as a matter of cause locomotion of nutrients to kernels of the weaker flowers shows a phenomenal decrease, then these kernels will be able to develop no more, and remain as blasted grains. In darkness physiological activity of plants declines more severly than under restricted sunshine but this condition continues only 4 days, therefore the locomotion of nutrients into kernels of the weaker flowers resumes after a while and these kernels will begin to develop again. (3) When upper five branches on panicle were cut off at several days after heading, the function of remaining flowers will become vigorous, and the locomotion of nutrients into that flowers will become plentiful. This treatment applied untill five days after heading diminished the sterilizing percentage, and the blasting percentage was decreased when the treatment was applied untill 15 days after heading (about 7 days after flowering of weaker flowers on panicle). And this treatment is more effective on the decrease of blasted grains than on that of sterile grains, because the blasted grains come of the declination of flower function and nutrient locomotion.

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Young rice plants (45 days seedings) were soaked 8 or 24 hours in α-naphtharene acetic acid solution as shown in table 1, then they were transplanted in pots, and cultivated as usual in grass house under normal condition. In 1948 half number of pots of each plot were kept for 10 days under a roof at the heading time to test the effects under restricted sunshine. (The auther formerly reported on the effects of restricted sunshine upon the occurrence of empty husks.) Length ot plants, number of culms per plant, number of leaves of main stem, and heading date were investigated according as plant growth, and after they were harvested, empty husks (sterile grains and blasted grains) were searched on the panicles and the sterilizing percentage ((No. of sterile grains)/(No. of flowers)×100) and the blasting percentage ((No. of blasted grains)/(No. of flowers)×100) were calculated on each plot, and compared respectively. The chief results may be summerized as follws : -- (1) In 1946, the environmental condition was very favourable for fertilization and maturation of rice plant and the strilizing percentage and the blasting percentage were researched on the main stems which would be more vigorous than other stems, therefor the sterilizing percentage and the blasting percentage were very low. With regard to the sterilizing percentage, there was no evident difference among the plots, but the blasting percentage was remarkably less in treated plots than in untreated plot. (2) In 1948, the sterilizing percentage and the blasting percentage were estimated on all panicles of every plots. In this experiment the sterilizing percentage as well as the blasting percentage was remarkably less in treated plots especially in D (0.002%-24 hours), E (0.001%-24 hours) and G plot (0.005%-8 hours) than in untreated plot, and these facts were more conspicuous under restricted sunshine. (3) It may be possible to infer from those results that the physiological function of treated plant may be more active than that of untreated plant. This difference of physiological avtivity has little effect upon the occurrence of sterile grains, so far as the occurrence of sterile grains is rare under favourable condition, nevertheless when the environmental condition is not so favourable it has an effect upon the occurrence of sterile grains as well as upon the occurrence of blasted grains. Generally, empty husks occur numerously under unfavourable environmental condition, therefore it may be possible to control the occurrence of empty husks by hormone-treatment.

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In this experiment, phosphorous fertilizer was supplied as shown in table 1 to examine the influence of phosphorus on the occurrence of empty husks in rice plants, and the results are summerized as follows: - (1) Generally speaking, when phosphorous fertilizer was supplied more and the manuring time was earlier, the heading time was earlier, the percentage of empty husks was less and number of matured grains per plant was more numerous. (2) When the phosphorous fertilizer was supplied no or a little in early stage of growth then was complemented until early August, number of matured grains per plant increased on account of increase of culms and flowers. (3) When phosphorous fertilizer was supplied after middle August, number of matured grains per plant hardly increased but the function of flower became active at the flowering time or thereabout, and the percentage of empty husks became lower. In this case, if the plant was very want of phosphorus until this time, matured grains increased though the maturing time was obviously delaied, and if phosphorous fertilizer was supplied too much, the vital function of plant was disturbed and percentage of empty husks increased. (4) Under condition of restricted sunshine, empty husks increased in weaker frowers on panicle (formaly reported by auther), but under condition of restricted phosphorous supply, empty husks increased in vigorous flowers as well as in weaker flowers, therefore the decline of the function of flowers owing to phosphorous deficiency should seem to be more strong and fundamental. (5) In cotton flowers, the amount of daily absorption of phosphorus markedly increases after meiosis and fertilization. (Biddulph, 1945), and in rice plants, when they want of phosphorus at heading time or thereabout, phosphorus removes into kernels from leaves and stems then the concentration of phosphorus in leaves and stems decreases. From these facts, phosphorus seems to have influence upon the occurrence of empty husks in consequence of playing important part in the normal development of pollen and egg cell and in proceeding of fertilization. Nevertheless, increase of physiological activity of plant, increment of absorption of other nutrient elements, and the variation of concentration of various elements in plant tissue may be attendant on the phosphorous supply, and these may have influence more or less on the occurrence of empty husks. Therefor it is difficult to discuss in this experiment which will be more important factor of the occurrence of empty husks phosphorus itself or other various facts attendant on the phosphorous supply.

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Summary For the wheat yield, the most impede factor is the climatic conditions during the maturity in the west Japan. When it goes on raining for long time, the wheat is remarkably damaged, especially, owing to the germination on the head. Some experiments were performed on the characters of grain and flour of the rain damaged materials. When the wheat was germinated on the field by the rainy weather, the characters of its grain and flour were deteriorated according to the extent of germination, but the degree of the deterioration was not so heavy as the appearaces of the kernels. In the laboratory milling tests, the germinated wheat in amounts as small as 5 and 1O percent had no appreciable effect upon the milling process. The percentage of steaight flour was higher in the superior wheat varieties, even when they were damaged by the rainy weather, than in the inferior varieties. The materials which were germinated for 3 days on the field, resulted in no appreciable effect upon the baking value. Not only is the percentage of ear garminated kernels important, but also the extent of the sprouting, for the wheat grading.

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1. By the recent war the fire-raged district was estimated to 50.49 km² in Osaka city. The writer carried out the investigation to study the utilization of wild plants in the district. 2. 16 families, 84 species as fodder plants and 21 families, 69 species as edible plants were found to be dominant. 3. In edible plants almost all of them contain plenty of fiber and buck, but it is not impossible to be utilized for food or flour food material and moreover they contain vitamin especially B₂ and C and plenty of phosphorus. It is desirable to make good use of them by taking care of cooking and harvest time. 4. When these wildplants are used as food and fodder, attention and care should be paid to 7 families, 11 species of legal poison grass mixed among them.

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Red clover (Trifolium pratens L.) is recognized as the most suitable plant for improving herbage on the grass land, and as a rotation crop on the field, from such the ecological features as the resistibility against snow damage and as the vigorous growth in early spring in the snowy Hokuriku district. Hence, the relation between the fertilization and the bees was investigated, as a fundamental datum in red clover production, at the Takada Farm of Hokuriku Branch of Agricultural Experiment Station in Japan. The results of this investigation were summarized as follows : (1) The relation between the percentage of the fertilization and the flowering period; the percentage of the fertilization is high in the first flowering time, and low in the second in generally. It shows an inverse relation against in Hokkaido, the reason, however, may be due to the differences of the bees visitation--mainly their sorts and visiting time. (2) From observations and investigations, it has been found that the pollination of red clover is effected by seven species of the bees--Bombus diversus S., Bombus igunitus S., Eucera difficilis P., Eucera sp?, Apis mellifica L., Andrena consimilis A., Megachila sasakiella C., (3) The relation between the fertilization of red clover and the flying-numbers of bees were as follows : i. Bombus genus most renders for services to the fertilization considering their flying numbers on the head flowers ; ii. Apis m. is not so effective in spite of the flying number being the most numerous ; iii. Eucera genus was recognized as considerable numbers on the flower head, and also has fairly connection for the fertilization. (4) It is an established fact that the Apis m. serves a little for the fertilization of the red clover, but not so easy finding that whether she can sips or not the flower honey.

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They were many experiments and observations on the effect of calcium fertilizer upon the growth of crops, and they are very important and interesting in sweet potato culture. The writer studied the effect of calcium upon the growth of sweet potato and two varieties Taihaku and Okinawa No.100 were used. Prominent differences in number of side branches, thickness of leaf, weght of living leaf, moisture contents of sweet potato, and size of starch granule were not recognized. But when calcium fertilizer was given at August 20, elongation of main stem was checked, transpiration and carbon-dioxide assimilation became vigorous, and chlorophyII contents in leaf was excellently increased, and yields of sweet potatoes increased 50% in variety Okinawa No.100 and 34∼40% in Taihaku. The physiological action that the calucium fertilizers give to sweet potato plants can not disucuss in this research.

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1. Studies on shape, process of growth and germinating character have been studied. 2. Close correlation of+0.604 has been found to exist between vertical diameter and weight of tuber. This correlation tendency is obviously observed in its early stage of growth. The growth in its vertical diameter, the rate of which decreases gradually, stops when the tuber becomes about 100 grams in its weight. 3. Correlation of+0.191 exists between the horizontal diameter and the weight of tuber. The above relation is observed not to be very close. Its horizontal dia almost finishes its growth before it becomes 50 grams in weight. 4. The knots of tuber increase in number as the tuber becomes larger, but there exists a certain limit to the extension of intervals between knots. Whether the vertical dia grows well or not, depends upon how many knots increase in number. 5. Close correlation of+0.78 exists between the increase of weight in the process of secondary growth and the weight of tuber. Particularly, the growth in latter term takes effect chiefly in the course of secondary growth. 6. The vertical section of tuber can be shown by the Equation of Circle stated below: b(x²+y²)+(a²-b²)y=a²b From the above Equation, surface area and cubic volume of tuber can be calculated. 7. At the beginning period when the formation of tuber takes place, no difference is observed between the growth of back side of tuber and that of front side. But as the time passes, the growth of front side falls behind. 8. The shape of vertical section of small tuber is nearly perfect circle, and it becomes spindle shaped as the tuber grows larger. 9. Immediately after the dormant period, tuber has generally the character of apical dominance, but the number of germinating tubers varies as the time elapses. As to the part grown in the course of secondary growth, the polarity becomes independent of its original tuber when it grows to some extent and germination takes place with that of apical germ.

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In the paddy field it is common to irrigate flooding water during the most part of growing seasons. There have been many observations concerning the meaning of flooding, but tbe experiments on the effect of flooding upon rice plant itself have not always been done enough. The author has planned these experiments intending to make this point clear up; this paper reports only preliminarily the tendency of gowth under flooding water. The rice plants were grown in Wagner's pots; flooding plots being 7cm flooded continuously, and the contrast being kept moist enough with no flooding. 1) In Kanto District, the temperature of early growing season of rice is rather low, hencc the continuous flooding promotes the growth according to its superiority in temperature. But later in summer, the soil aeration seems to become a important factor, and flooding is rather disadvantageous for growing of rice. 2) Flooding affects the structure of the lower portions of stem and may weaken them mechanically; weakness may be chiefly due to thin wall of culm and want of mechanical struetures.

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In the Yangtzekiang Delta of Central China there are two formal kinds of cultivated rice plants, Sheng-Doh and Kuang-Doh. The former is presumed to be originated in Indian rice plant type and is very early harvesting although it thrives so vigorously. The latter, on the contrary, is genetically included in Japanese rice plant type and usually harvested in late fall. Each form is distinguished from another by its plant habit, coloring, shape of grains, maturity etc. collectively, apart from the troublesome progeny test obtained from crossing between them. In some cases, however, above-mentioned characters are not sufficient for the items of distinction from both types due to presence of varietal diversity in Sheng-Doh form. Firstly, in this report it is explained that the young leaves length of seedlings is characteristic of Sheng-Doh, Kuang-Doh or other rice plant forms, respectively. That is, a most of Sheng-Doh and Indian varieties have the longer first, second and third leaves than those of Kuang Doh and Japanese varieties. And only a few Sheng-Doh varieties, which have been already pointed out as peculiar ones that, for instance, have closely resembled to Kuang-Doh form or been resistant against drought, possess the exceptionally shorter leaves than the normal. Secondly, as to the main stem node which develops the first tillar, we can recognize the rather distinct difference in the written forms. The first tillars of most Sheng-Doh, Japanese land rice and Indian varieties appear from the second of their stems, but, on the other hand, those of Kuang-Doh and Japanese water rice varieties usually develop from the third node. And some Sheng-Doh varieties, which have been known as peculiar characteristic ones regard to the morphological or physiological properties, have the same tendency of tillering to the Kuang-Doh form. Thus, the proper characters of rice seedlings, for instance, length of leaves and first tillering position, may be serviceable marks to distinguish the difference between Sheng-Doh and Kuang-Doh quickly and to find out the peculiar variety which may bave latent characters for any ecological conditions.

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Practical studiess on the injurie of cool weather in rice plant. Report II Ripening optimum outdoor temperature and critical heading date for it. As before reported, the average temperature of maximum and minimum in 40 days after heading necessary for full development of rice grain in the Tohoku Region's weather condition is over 22°C. In order to gain the temperature, the date of heading must be earlier than August 16 in the average year at the Fujisaka Experimental Farm in Aomori-Prefecture, and August 26 at the Obanazawa Experimental Farm in Yamagata-prefecture. Namely, these date can be called the critical heading date for full development of grains.

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Summary Summer weeds in the field of Kanto and its neighboring region were generally surveyed in 1946∼1948. In this districts summer weeds was found to have 91 kinds of weeds. The results ot researches are summarized as follows ; Name of weeds Percentage of weight Digitaria ciliaris pers. 40.5 Portulaca oleracea L. 10.9 Cyperus spp. 9.7 Mallugo stricta L. 5.7 Amaranthus blitum L. 2.9 Equisetum arvense L. 2.5 Polygonum nodosumpers 2.1 Acalypha australis L. 2.1 Panicum crusgalli L. 1.7 var. submutica Mey Other 82 weeds 21.9 Digitaria ciliaris pers may be from this table assumed absolutely predominant in this districts in the summer season.

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1. Analysis of drought damage was made examing (a) damage by injurious insects and diseases and (b) drought damage from physiological and morphological relations. 2. As for physiological and morphological drought damage, varietal differences were observed by detecting the decreasing percentage of height of plant, number of stems and weight of panicles compared to control. In that result fairly high negative correlation was recognized between the decreasing percentage of number of stems and that of weight of panicles. When the percentage of crop yield decrease was compared, heavy panicle varieties of early on middle ripe type has shown less percentage than tillering late ripe one. 3. Among injurious insects Sesamia inferens WALKER keeps comparatively greater part. When varietal differences of insect damage were compared by injured panicle weight percentage for control/injured stem number percentage, it was recognized that the result came together with that of heretofore. 4. As for disease damage, that of the blast disease (Piricularia 0ryzae BRI. et CAV.) at spike-pedicel was found to keep almost all part. When compared by the method mentioned above the result of varietal differences came near that generally recognized. 5. Fairly high negative correlation seems to exist between outbreak of the blast disease at spike-pedicel by drought and degree of the development of the silicificated-short-cells in the epidermal tissue at spike-pedicel. 6. In test of drought resistance it is necessary to make analytical examination discriminating physiological and morphological resistance against that to diseases and injurious insects.

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Various foreign sources of information have recently shown us that the application of 2.4-D (2.4-dichlorophenoxy acetic acid) is effective for the weed control. Therefore, the writer tested a possibility of adopting this method in paddy condition. From several varied experiments, a spray of 0.05-0.1 percent 2.4-D in the form of either sodium or ammonium salt in water at the rate of 75-150 liters per 10 ares on weeds between the growing rice plants on well-drained paddy field in the mid-or late July has given desirable results, this method was so effective that, with the exception of Echinochlon Crusgalli Beauv. all kind of weeds such as Aneilema Keisak Hassk., Monorkoria vaginalis presl., Lindernia Pyxidaria all., Rotala indica Koehne. ver. uliginasa Miq. cyperus difformis L. Fimbristylis miliacea Vahl., Elatine orientalis Makino, Echipta alba Hassk., Hleocharis acicularis R. Br., etc., were killed within 1-2 weeks, nevertheless no injury to the rice plants was recognized. It may be recommended for the control of weeds on th paddy field to apply 50-75gr of 2.4-D per 10 ares, as it gave as much rice yield as that of the ordinary weeded plot. 37.5gr per 10 ares (0.05 percent solution at the rate of 751. per 10 ares) seemed to be too small doses and 150 gr. per 10 ares too much dose, each of which decreased the rice yields 15 percent and 10 percent respectively as compared with the ordinary weeded plot, although the rice yields of both plots was superior to that of the unweeded plot which about 35 percent less yield than the control.

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Summary 1. During the springtime of 1948 an investigation was made on waste, reclaimed, and farm lands in acid-soil as well as limestone regions, in order so determine the relation between the distribution of weeds and the reaction of soil on which they grow. 2. The chief species of weeds which grow on waste, reclaimed, and farm lands were as follows. [table] 3. The following species were abundant on acid soil regions or limestone regions. [table] 4. In proportion as the soil matured the therophytes, weeds of poor sociability, of high constancy and in bloom at that time increased in number of species.

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1) On the previous paper, we distinguished the following three types of crops, according to the stomatal density on the upper and lower surfaces of leaves : 2) Summer type : The stomatal density on the lower surface of the leaf is always higher than that on the upper. 3) Winter type : The stomatal density on the upper surface of the leaf is always higher than that on the lower. 4) Intermediate type : The stomatal density on the upper surface of the leaf is higher than that on the lower during the younger stage of life, and is lower in the later stage. 5) Among the environmental factors, light, humidity, soil moisture and others, light is most universally responded by stomata. Under the control of light, we observed the change in stomatal density of cereals and found out the following fact. 6) The relative number of stomata on lower to upper surface of the leaf is nearly 1.00, when grown in darkness, notwithstanding species and varieties of cereals. 7) It seems, from the facts shown above, the cereals have ability of producing the same number of stomata on both upper and lower surfaces of the leaf. Adaptation of this ability to the light conditions causes the distinction of the three types ; Summer, Winter and Intermediate types.

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It has been reported often that the growth of rice plant after transplantation would be retarded by a continual dry weather. There are also many discussions about the suitable time for irrigation in case of the direct sowing. We studied the effect on the growth of rice plant by changing irrigation period using pots ; this year (1948) the period was set from the time of transplantation ot the harvest. The method of experinment ; ……… We conducted the following experiments dividing the pots into three sections and each section was started on the fifth of July. The first section was the standard and had been filled up with water right after transplanting. The second and the third section had been irrigated from the second of August, 1948 and the twenty-fourth of August, respectively. Results ; ……… The 1st section grew favorably from the beginning to the end. The 2nd section showed a little inferior to the 1st section. At the 3rd section, we found the height of the plants and the number of the leaves were worse than those of the 1st and the 2nd section. While scarce coronal roots, We observed many branches and hair roots at the 3rd section. Summary ; ……… The 3rd section showed a tendency to rice plant cultivated on the upland field, but it's growth was retarded about 5 days comparing with that of the 1st section.

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Most pH value of plant were measured are of the expressed sap of tissues. The expressed juice, however, consists of water which lies in the intercellular spaces or conducting tissues and cell sap with some plasm substances. It is impossible to measure the pH value of a definite part of a individual cells by such a method. Nevertheless, we might know the relation between the pH value and disease by this method, when the plant tissue set up necrosis. However, in the case of studing the mechanism of the resistance to disease, the pH values we need to know are of the earlyer or normal stage of cells rather than necrosis. In such a case, the most ideal method is vital staining one. Thus, a number of pH value by this method were obtained by others. But it is regrettable that this method is not yet popularized. Then, to tried to it, we tested about 80 kinds of dyes on the permeability, intrability, and toxic character to vegetable plasms, and tried to reform microscopic colorimeter (not microcolorimeter). In this paper, we should like to report chiefly the microscopic colorimeter with some results obtained as a sample. On the rests, we shall report in another chance. The principle of the microscopic colorimeter divised is utilized conversely the principle of Abbe's drawing apparatus as shown in figure. We made standard colour solutions by adding original dye solutions (0.1%) in buffer solutions, and then set them in apparatus. We can compare tone of colour between stained cells and standard. By using this apparatus, we may distinguish acculately to the first place of decimal in pH value. Furthermore, it has good points required when using this method as follows : (1) It is possible to change easily the concentration or components of standard solutions. (2) It is possible to use any artificial light as a light source of microscope, owing to make equal quality of light by changing filter which illuminate standard solutions. The plant cell used were the 4-5 th layer of cortex of root-tip at 8mm. from the top of Barley. Dyes solved in tap water (pH 6.8) and the concentration is 0.01%. Dyes used are neutral red, neutral violet, cresol red, bismarck brown, brom thymol blue, methyl red, congo red, alizalin red S, congo rubin, phenol red, brom cresol purple, and rosolic acid. Results obtained are as follows : vacuole pH 7.4, plasm 6.6, nucleus 7.4-7.2, and membrane 6.0. [figure] C. Standard pH solutions, c is a side view of it. P. Plisms. F₁, F₂, f₁, f₂. Glass filters. T₁, T₂. Electric transformers. S. Slide glass with a subject. M. Microscope.

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1. According to the yield records of two years (1947-48), varieties of different plant-types responsed to the dressing and spacing in the following ways. V.1 (Yashima-senbon), V.3 (Ginbozu-midashi), V.4 (Norin-22) and V.7 (Kanto-9) belonged the 1-group (suitable for heavy fertilizing), V.2 (Tamanishiki), V.5 (Sady Wright) and V.6 (Boshito-chinese rice) to the 2-group (suitable for less fertility), and V.3, V.4, V.5 also suited to sparse spacing (the 3-group) while V.1, V.2, V.6 and V.7 suited to dense spacing (the 4-group). 2. (a) As to the response of the varieties to the application of ammonium sulphate, the yield increase was not always in proportion to the increase of the total nitrogen absorbed by the plant, but it was rather connected with the efficiencies of a unit amount of nitrogen absorbed by the plant to produce the paddy grains. (b) While, the yield increase of varieties in the case of narrow spacing of plants was highly correlated with the increase of nitrogen content in plants. 3. (a) In the heavy dressed field the amount of nitrogen in plants of the 2-group increased more notably in the early stages atter transplanting, and at the same time, the soluble nitrogen content per total nitrogen increased more remarkably. As the result of it, the capacity of absorbing new nitrogen in the later stages became lower as compared with none dressed field. But this inversion time differed with variety. (b) Varieties in the 2-group had smaller nitrogen content per total dry matter in plants in the vegetative growth stage than the 1-group, and they lost rapidly to assimilative ability of their leaves after heading. They also showed more lodging. 4. Varieties in the 3-group have an ability to absorb anew much amount of nitrogen during the following period, in proportion to the amount of nitrogen that have been already absorbed into the plant. They showed less content of nitrogen per unit area of living leaves, and showed higher content of ammonium nitrogen per fresh matter in plants, as compared with the 4-group. 5. Some theoretical considerations were given to the results above mentioned.

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1. This report is the methodical development of my long investigation on the yielding efficiency of Japanese rice variety. I use this method of calculation in some past of my investigation. 2. I use the "Standard deviation method" as the relative expression of heading period, stem length, numbers of stems and yield per tan of rice variety and I think it is a convenient method and it is a method or reducing the eror to use the standard deviation method. And I proved this by the following example. 3. In a group of variants I call the deviation of each variant from the representative value of variants (I call this Standard value, and it is convenient to use the mean value, ) standard deviation. When I need the relative value only, and when I can regard the representative value of variants as the same, by useing the "Standard deviation method" I can eliminate the effect of the deviation of mean, such as year factor effect and soil heterogenity effect and can express the relative factors with less errors and by more exactness. 4. In calculating the error of "Standard deviation method" I take the standard deviation value as a variant, calculate the standard deviation, proobable error, and probable error of mean by the normal metbod. 5. The reliability of the estimate, the error, calculated by "Standard deviation method" is normaly increased by a great scale. In my example it increased twice. 6. I think, the "Standard deviation method" may be inferior by the accuracy to the "Student method", but I thiv it is more conenient and more distinct. 7. I think, the "Standard deviation method" does not abandon other method of calculation. The "Standard deviation method" can express the factors accurately by the co-operation of other method, such as the ordinaly method useing absolute number.

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Rice seeds infected by drown spot disease, Ophiodolus Miyabeanus show marked decrease in germination and retardation in the following seedling growth, especially when they are sown on dry soil, and the fact should be considered to be one of the main causes of the failure in germination and seedling stand in direct sowing of rice without transplanting.

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Rice plants (Var. Aichiasahi) were grown in pots under 8 different nutrient conditions as follows : (1) Full nutrients (F), (2) Nitrogen only (N), (3) Phosphorus only (P), (4) Potassium only (K), (5) Without Potassium (NP), (6) Without Phosphorus (NK), (7) Without Nitrogen (PK), (8) No nutrients (O). Leaves of the definite orders were sampled from the seedling of all plots and then "heat coagulation method", which has been devised one of the authers, was applied as follows : The sampled leaves were ground out carefully and the solution were diluted by adding 30c.c. dist. water per 1gr. green weight. After filtrating it, 5c.c. solution was taken and at 60°C in the water bath. At the sametime, another 5c.c. solution was taken and added with 0.5c.c. of 10% NaCl solution as coagulater before heating as above. Then the time required for the appearance of coagulantion was measured. It was found that the coagulation generally appearance earlier in the plots which containd nitrogen such as F, N, NP, NK, than in those without nitrogen such as P, K, PK, O. Moreover, this tendency was recognized with the plants at any stages of growth as far as this experiment goes.

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A study was made of the effects of different quantities of fertilizers (N, P, and K-manure) upon protein content of wheat grains when the plants were grown under a condition with warmer winter and rainy spring. The results obtained were as follows ; (1) Among three essential elements of fertilizers, nitrogen had considerable influence upon percentage of protein in wheat grains ; a series of N-manuring experiment ranging from none to 150 pounds per acre in the form of sulfate of ammonia revealed that protein content of grains from the plot without N-manure showed the highest and that of grains was at first decreased with the increase of the quantities of N-manure to some extent, but it was gradually increased with the application of an excess of N-manure. (2) Phosphorous manure had slight effects on the N-content ot grains and there was found a declination that the increase of P-manure resulted the decrease of the protein content of grains. (3) Potassium had almost no effect on the protein content. (4) It was known in this experiments that a large yield of high protein wheat can be secured by the sufficient supply of available nitrogen for the wheat plant during the whole growing period.

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In comparative storage tests of cereal grains, corn, wheat, naked barley and rice grains dried to 12 percent moisture content were held for storage in containers consisting of Japanese rice straw bags and air tight tins. Periodic analyses on the conditions of the grains revealed that, in all cases, deterioration of the grains proceeded at a much rapid rate in the straw bag than in the tin container. There were changes not only in the physical properties but also biochemically of different degrees. The naked barley was highly storage-tolerant showing least changes, followed by rice and wheat. Corn was found to be least suitable for storage in the rice straw bags. Under the sealed condition in the tin containers, all grains were preserved with less changes, particularly this was true on many of the physical properties. Biochemically, however, the order of deterioration was naked barley least affected, wheat slightly affected, while the corn and rice ranked lowest among the four grains tested.

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Though the coleoptile is typically a two-bundled structure, occasionally a higher number of strands occur. In this paper the author will show at least two cases on the origin of them. (1) First case : After originating from the lower strands simultaneously in like manner and going together, the normal and supplementary bundles are separated each other. (2) Second casse : The supplementary bundle originates isolately in the cortex of the coleoptilar base. Frequency of appearance of the supplementary bundle in the second case is larger than that in the first case. Hereafter in discussing the origin of the supplementary bundle of the coleoptile the two types may be distinguished.

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1. A main cause for the enervative sterility of buckwheat under cultivation at high temperature are defined. 2. The enervative sterility depend on high temperature of buckwheat are described that it is impotence by incomplete-development of female, in the flowering flower organ. 3. These incomplete-development of females increased very high at above 28 C. day temperature, and it revaration-ratio and the sterility has been a very possitive correlation. 4. The male organ of such flower could not see a variation like female. The pollen of incomplete flower has, partially, decrease of the starch content, but it has a fertile-power. 5. By alternating temperature, this female deficience could give normal type. For it is, during at summer season, the flower of buckwheat at cooler night and cooler day are normal developed female flower. 6. The revaration-ratio of incomplete flower was few at cooler night than coller day. 7. As a result of our observations it is believed that the enervative sterility of buckwheat under high temperature are depend on assimilation-respiration ratio.

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1. To what extent the change of moisture in tuber, exerts influences upon the cultivation, storage and utilization of Jerusalem Archichocke, has been studied. 2. Because of the non-existence of cork layer, tuber can easily exhale or absorb moisture. 3. To dry up the perfect tuber until it becomes constant in volume, it takes seventy to eighty days indoors, and thirty days outdoors. If the tuber is cut and dried, one day will be enough for the purpose. 4. For drying tuber, the period of December to January is preferable to that of March to April. The reason for the above is that, at the begining of spring relative humidity is least in the year. 5. When the dried tuber is soaked in water, it nearly restores to its original form in two or three days. 6. If the tuber is dried until the moisture in it becomes about ten per cent, there is no risk or deterioration even in rainy season. For the reason stated above, it is suited for storage and transportation as forage and raw material. 7. When the tuber is dried to suitable exent, germination is retained and the tuber falls into a state of compulsory dormance. Consequently, the consumption of nutriments is prevented, enabling the seed time to change. 8. If the dried tuber is used for seed, the tendency is observed that the growth is accelerated and the yield is increased. But if the tuber is dried excessively, the germinating power will be lost. 9. Close correlation of +0.99 has been found to exist between the specific gravity of oozings and the total amount of sugar contained therein.

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In this study it was made to clear the effect upon the seed development, especially upon the oil contents, Iodine Value and protein content, changing the soil-moisture as just after flowering or 56 days later (as the Iodine Value begins to turn). The results of this experiments summarized are as follows : 1. Putting under dry condition as 30% moistured soil after flowering, the growth of main stem in retarded subsequently. With increase of soil-moisture 30% to 50%, the elongation is recognized. 2. Being under dry condition after flowering, the number of flowers slighty decrease. 3. The elongation of gynophore is slow under dry condition, but as soon as reached to soil, the fruit are developed quickly. 4. The peanut crops cultivated under well-moistured soil grow better than under dry condition. 5. The seeds on the peanut crops grown under 50% moistured soil are well developed than 3O% condition. 6. The oil content of the seed produced under well-moistured soil is larger than dry condition, while on the protein content is contrary. 7. The Iodine Value of the oil produced under less-moistured soil is higher than more-moistured.

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In order to know the interrelation between the infection of potato virus disease and the seasonal variation of aphid population, investigations were carried out on the Chugoku branch farm in three successive years from 1946 to 1948. The results of the study are summarized as follows:- 1. In Himeji district, the peach aphid (Myzus persicae Sulzer) and Cotton aphid (Aphis gossypii Glover) are the main species attacking the potato. As to the ecological type, apeterous female predominated in all three years, throughout the potato season. 2. The infestation of aphids on potato plants generally began at about the end of April, just after the potato sprouted ; a month later, at about blossoming time of potatoes it reached the maximum, and at about the middle of June, it terminated. In the fall crop, the infestation began early in October and ended by the end of the 10th of December, and generally speaking more aphids were observed on potatoes in fall than in spring. Some differences, however, were observed during the three years. These appeared to be due mainly to the difference in growth as a result of growing conditions. 3. The rate of increase in virus infection is closely connected with the number of aphids. It was also confirmed that from 20 to 30 days were necessary for the virus poison introduced by viruliferous aphids to be translocated from leaves to tubers. 4. The above mentioned fact offers the foundation in determining the date of harvesting in order to secure disease free seed tubers in the warmer region ; i.e. if seed potatoes were dug up in spring within some 20 days after the maximum infestation of aphids, we can safely say that they are practically virus free. 5. In fall crop, notwithstanding the more infestation of aphids than in spring, there was no significant increase of virsu, indicating the importance of fall crop for the production of seed potatoes.

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Further studies on the chimeras appearing in the storage roots, stems and leaves of sweet potatoes were made, and some new data are given in the present paper. Agronomic variety OKINAWA-No.l00. In the ordinary strain of OKINAWA-No.l00, the surface colour of storage roots is light red. From this strain, one storage root that was light yellow on its entire surface appeared by somatic mutation. The storage roots of the next generation propagated by stem cutting from this mutant were not always light yellow, and there appeared often the individuals having storage roots that were light red, light yellow or striped or flecked with both colours, though it seems to be accepted usually that mutant colour may be kept in the next generation thus propagated. In view of the fact observed the following passibilities may be cited regarding the causes of this phenomenon. (1) In the light yellow or light red storage roots, the genes in regard to the colour were unstable in the cells of meristems forming the periblem of atems, so that the next generation of such storage roots is not fixed to their colour. (2) Even if the surface of storage roots is light yellow or red, the genes in the cells of meristems forming the periblem of stems may be different from those of the surface of storage roots, the cells of different kind being distributed as Chimeras in the tissues. So that the stems derived from a single storage root of an uniform colour may form storage roots of different surface colour, according to the genes in the tissues from which the stems were originated. Agronomic variety Gokoku. In a large cultivation of GOKOKU, a chlorophyll deficient mutant was found. This plant had four nodes, and the shoot from the undermost one was provided with normal leaves and stems, while those from the other three had chimeral leaves and stems in white and green or in red and green. Observing this chimeral plant morphologically and historogically, the sectorial, the periclinal and the mericlinal conditions in chimeral consitution were found. In the cultivation of OKlNAWA-No.1OO and GOKOKU and other strains of sweet potatoes, various mutants in the colour and other characters occur quite frequently, so that it is quite necessary to pay precise attention in selecting seed storage roots in order to avoid the deterioration of the strains.

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The relationships between the growth habit of so-called summer vers. autumn soy beans (reported by T.Nagata in 1948) and other characteristics, which were investigated parallel, found as follows ; (1) The interrelation between the growth habit of summer vers. autumn soybeans and the earliness of flowering of the tested varieties was so closer that correlation coefficient showed as in r=0.85. Therefore, the summer type found as the earier, the autumn types the later, the intermediate types the medium late varieties. (2) 4 types were observed in the changes of flowering days (from germination to flowering) according to the differrent periods of seeding. These types were called as "the Ecological types of flowering". (fig 1) The autumn types belonged to the type I and type III, namely their flowering days were remarkably shortened when they were sown in both July and August. The type II and type IV, namely those not remarkably shortened even when they were sown in July and thereafter, were recognized mostly in the summer types. In the intermediate types, there were found all these 4 types existed. (3) It was found that the first flower was born at the heigher nodes in the autumn types and at the lower in summer typer. And the correlation coefficient calculated between these characteristics was r=+0.86. The changes in order according to the different seeding times was found as same as in that of flowering days. (4) The closer relationships between the growth habit of summer vers. autumn types and the stem length, number of blanches, grain weight per plant, and the weight of a plant were observed. Therefore, the autumn types produced comparatively more yields than the summer types. The pseudo summer types (SIp) was long as in stem length, but it had a small number of branches. (5) There was found no closer relationships between the growth habit of summer vers. autumn soy beans and the morphological characteristics, namely the forms and colour in various parts of the plant. Therefore, differences. in summer vers. autumn types were defined purely as physiological and ecological.

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The auther has been made an experiment to see the influence of natural low temperature of planting time upon the developmental process of tabacco seedlings, which were grown under different conditions. The seedlings to be test were divided into six kinds by the difference of the next growing method, and each of them were separately cultured in green house (high temperature plot) and open field (natural low temperature plot.) respectively. The kind and the growing method of seedling. [table] The result of this experiment can be summarized as follows ; The growth and flowering of all plants exposed to natural low temperature were delayed compaired with that to high temperature, and their total leaf number has decreased. But an exception, in this case, was recognized ; the seedlings grown roughly in seed bed of open field were flowered very rapidly, and their total leaf has remarkably decreased. According to the above results, it is low temperature affects the development of tobacco plant as well general winter crops and accelerates at least, the flower initiation. Moreover, it is suggested that the reaction degree of seedlings itself to this temperature will be varied clearly by their different developmend and nature.

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According to the auther's observation, the bees that visit the red clover in Sapporo, Hokkaido were as follows : Bombus wustneii chinganensis Reinig, B. speciosus Smith, Eucera sociabilis Smith, Andrena spp. and Apis spp. Besides the bees mentioned above, B. jonellus Kirby and B. muscorum L. also visited the red clover in Hokkaido, especially the latter was seen in considerable numbers. Male of Eucera sociabilis Smith were most numerous and a large number of bees of Apis spp. were also working on the red clover. B, wustneii chinganensis Reinig most active but was not plentiful. In Fukuoka, Eucera sociabilis Smith, Andrena spp., Anthophora villosula Smith and Apis spp. were seen on Trifolium pratense L. The cause of shortage in number of bees visiting the red clover in Fukuoka was seemingly attributable to minority of that plant ; if red clovers were abundant those bees might be also more numerous.

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This experiment was planned to determine what kinds of bees contributed to the production of the seeds of red clover cultivated in the cage. The cage was covered with cheese cloth, and it was placed over the pair of isolated plants previous to their blooming. Five to ten individuals of bees were confined to each cage. Bombus wustneii chinganensis 〓, ♀, Eucera sociabilis Smith 〓, ♀ were the most effective pollinators in the cages. Andrena spp. and Apis indica japonica Radoszkowski were of little use in setting pods and seeds. The nectar sucking method of Bombus speciosus Smith 〓 was abnormal and it was least serviceable as the pollinator of red clover. Honey bees were observed gathering pollens, however, they sucked the nactar after beginning of the wilting of flowerheads. It was doubtless that B. muscorum L. 〓, B. jonellus Kirby 〓, B.diversus Smith ♀ and B. ignitus Smith ♀ were effective pollenizers of red clover.

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This study was planned to determine whether co-existence of other nectar plants has influence upon the pollenizing activity of bees in the cage. Nectar plants, the alsike clover (Trifolium hybridum L.) and the white clover (Trifolium repens L.) were used for this experiment. When the other nectar plants bloomed simultaneously with the red clover, pollenizing activity of Bombus wustneii chinganensis Reinig 〓, ♀ and Eucera sociabilis Smith upon the red clover decreased slightly as compared with the case when the red clover was cultivated alone. In the case of Apis indica japonica Radoszkowski the seed production of red clover was decreased also some extent by the co-existence of those competitive plants. The seed setting ability of red clover by Andrena spp. was most decreased in the same condition mentioned above.

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In the crossing of red clover, the utilization of bees as the pollenizing agency is very convenient. However, if the two plants being desired to cross, are separated each other too far this method cannot be applied. This experiment was planned to determine whether the cut flowers of red clvoer are utilizable as a pollen plant in the cage containing Bombus wustneii chinganensis Reinig 〓 or not. According to the results obtained in this experiment, it may be said that this method is very simple and nevertheless is successful to gain adequate F₁ seeds for the progeny test so that the cut flowers can be used a pollen plant in the red clover breeding.

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1. This brief report deals with the experiments concerning the difference of the cold resistance between diploid and artificial autotetraploid plants of Brassica chinensis L.. 2. By the degree of wilting (=wilting %-age : number of wilting leaves/number of whole leaves) under low temperature, -2.3°C, the 4x plants were observed clearly to be hardier than the 2x ones. 3. The osmotic pressure recorded in the cells of 4x plants was always higher than that observed in those of 2x ones. 4. No remarkable differences were observed between the 4x and the 2x in the content of water, total nitrogen, and total sugars in the plant tissue. It was, however, recognized that they differed in the soluble sugar content, which might have taken an important roll in causing the difference in their osmotic pressure.

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In order to confirm the result of the first experiment concerning the cold resistance of artificial polyploid, similar one was carried out using 2x and 4x plants of Eruca sativa Mill.. The superior winter hardiness was also displayed by the 4x plants with higher osmotic pressure than in the diploids. Here again no remarkable differences were noted between 4x and 2x in the content of water, total nitrogen, and total sugers in the plant tissue, except in that of soluble sugar. It has been suggested strongly that the difference in winter hardiness might be due to the difference in osmotic pressure ; and that the difference in osmotic pressure might be due to the difference in soluble sugar content, quite the same as in the case of the first experiment with Brassica chinensis L.

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We carried out cyto-histological observations to the tuberization of potato plant. The results are as follows. 1. The stolon emerges extrophly from the node of subterrenean main stem at once after germination. Yasui (1946) described that the emergence of stolon would be induced by the differentiation of flower organ in the growing point of the terrestrial main stem. The vuscular bundle of stolon develops weakly and scarcely in comparison with the main stem. 2. The stolon-top begins to change its form as soon as it ceases to "Tuber formation period". The most characterized results in cytohistological observations of this period are as follows. 1) Conspicious increase of mark in comparison with rind. 2) Development of interparenchyma cell layer. Increases of each tissues are induced by enlargement of cell and increase of cell number. 3. "Tuber swelling period" is continuous to "Tuber formation period." In this period every tissues increase in company with tuber swelling, but rate of increase of mark is more than it of cortex at the beginning of this period, and after this the rate stated above are nearly no difference in every tissues. Enlargement of cell in every tissues is continuing to a limiting point of tuber swelling process, this point is about in J stage (tuber weight about 140g). Increase of cell number is considered by relative growth rates of both increase of tissue and enlargement of cell, and it is continued to the latest stage of swelling period. 4. Small starch grains are observed at first in the endodermis of cortex and they spread to every tissues and increase their size (Trans. Dimension+Longi. Di./2 in measurement). On the other hand they are formed newly during tuber swelling period. 5. The cork layer of tuber is commenced to form in III stage of "Tuber formation period" and completed quantitatively in the beginning stage of "Tuber swelling period, " after this its thickness is decreased and become to completed protected layer.

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(1) The seedlings of paddy rice (about 35 cm in height), the root of which had been cut off by a knife, were put, for 24 hours in the laboratory, in the 1% solution of straw-ash, 0.5% of Ca(OH)₂, 0.l% KC1 and water (control), respectively, and then all were cultured in water for a few days, during which the root-growth being wxamined every day. It was noticed that the root-growth during the water culture was hastened in the treatment with either straw-ash or KC1, compared with the control, but not in that with Ca(OH)₂. (See Table 1.) (2) The root-growing activity of the leaf-stalks of sweet potato were tested in the same way as explained above, resulting in that the root-growth was accelerated in either the straw-ash or KC1 treatment while it was rather reduced in that with Ca(OH)₂. (See Table 2 and Fig. 1.) (3) The stems of chrysanthemum were cut off and put in straw-ash solution and also in the Ca(OH)₂ solution, for 24 hours, the KC1 treatment being omitted in this case, then they were planted on the field, all of which being proved alive, and they were tested with regards both the root-forming and the plant growth with the results that the root-growth promoted in the straw-ash treatment, accompanied with the vigorous vegetative growth, but the reverse was the case in the Ca(OH)₂ treatment. (See Table 3 and Fig, 2.) (4) Judging from the results noted above, the hasting of the root-growth by straw-ash seems to due to the Physiological action of Potassium but not of calcium, contained in the material. (5) Furthermore, the hasting of the root-growth by potassium, it is supposed, is drived from the high assimilaten products by the above-noted material. (6) In cultivation practice, straw-ash is widely used in our country, at least, on the nursery, and this seems recommendable in favour of hasting the root-growth of plants concerned after the transplantation. But it is worth while that the straw-ash treatment with seedlings or cuttings is studied in regard to the modes of its application with various crops for increasing the efficiency of its hasting action of the root-growth.

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The physiological and ecological characteristics which crops show in the course of their growth, are responses of potential energies in crop body to environmental factors. Potential energies which seeds of crops hold, may response in a similar way when seeds are placed under similar conditions. From this point of view, the author tried to determine catalase activities in seeds of various kinds of rice plants at both temperatures, 10° and 30°C (36 varieties of lowland and upland rices grown in Japan, China and tropics). And the thermosensitiveness of the ferment expressed by the ratio of the differences between activities at both temperatures to that at low temperature, was calculated in each varieties. The results were as follows: 1. The activity at l0°C was almost higher in earlier varieties than in those of later heading. The correlation value between the activity and the duration of the growth was shown in r=0.539. 2. The activity at 30°C was almost higher in later varieties than in those of earlier heading. The same value as shown above was r=-0.414. 3. The thermosensitiveness of the ferment, was higher in earlier varieties than in later ones. The correlation value between the sensitiveness and the duration of the growth was shown in r=-0.693. The earlier varieties of rice plants are used to be grown in relatively cooler regions and the later ones in warmer regions. The earlier varieties head remarkably earlier when they are grown in warmer regions. Potential energy, namely the ferment in seeds of rice varieties used, showed such corresponding responses to temperatures as plants do in their growth.

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1. An apparatus was devised to facilitate vital observation, without injury, of seedling roots of rice and several other crop plants under a microscope, and to measure the rate of protoplasmic streaming in the root hairs under various temperature conditions. 2. The rate of protoplasmic streaming increased with temperature in an exponential curve, but above certain temperature, the rate began to decrease. Between l0°C. and 25°C., Q₁₀ values were 2.0 in rice plant and 1.6 in wheat plant. 3. The difference in the cultivating temperature (15, 20, 25°C.) before the measurement had no effect on the rate of streaming in rice plant. 4. The temperature at which the maximum streaming rate was observed differed with species of crop plants. In wellwater (pH 6.6), it was 33°C. for corn, upland rice, paddy rice, tomato and cucumber; 32°C. for wheat; 30°C. for spinach; 29-30°C. for naked barley; 29°C. for barley and radish; and 27°C. for rape. Thus, it was found that the temperature was high in summer crop plants and low in winter ones. 5. The rate of protoplasmic streaming differed with species of plants. In wellwater (pH 6.6) of 20°C., the rate was rapid (6-8μ/sec.) for wheat, barley, naked barley, upland rice and paddy rice; moderate (5-6μ/sec.) for tomato, rape and corn; and slow (4-5μ/sec.) for spinach, radish and cucumber. 6. A slight varietal difference of streaming rate was observed in varieties of rice and wheat plants, but the temperatures for maximum rate did not differ with varieties. 7. The streaming was observed to stop at high temperature, within 40-45°C. with rice plant. The temperature was somewhat higher with the southern rice varieties or summer crop plants than with the northern rice varieties or winter crop plants. 8. Under certain limit of temperature, the streaming stopped at high temperature and recovered after the lowering of temperature, but it failed to recover, if the tempereture exceeded 45°C., with rice plant. 9. The streaming was also observed to stop at low temperature within 0-10°C., with rice plant. 10. When the temperature was lowered to 0--2°C. with rice plant, the streamig recovered as the temperature rose if the water did not freeze and the temperature did not rise suddenly. 11. The rate of streaming in rice plant increased somewhat in dilute solution of H₂O₂ (0.00003-0.000003%) in wellwater, but in a higher concentration (0.003%) the streaming stopped. 12. The rate in rice plant decreased in dilute H₂S solution (0.000009 mol) and in a slightly higher concentration (O.OOO625 mol) the streaming stopped. 13. The rate in rice, wheat and barley plants decreased in dilute solution of KCN (0.0001 mol) in wellwater and in a slightly higher concentration (0.00l mol) the streaming stopped. 14. The rate in rice plant in boiled wellwater decreased after prolonged submersion. 15. The temperature for maximum rate in rice plant was slightly higher in dilute H₂O₂ solution, but it was lower in wellwater (after prolonged submersion) or in dilute KCN solution. 16. The rates of streaming in the roots which had grown in wellwater or in air (on moist filter paper) were observed respectively. With paddy rice, the rate at high temperature was more rapid in the former than in the latter. With wheat and barley, however, it was more rapid in the latter. With upland rice, the tendency was intermediate. The temperature for maximum rate did not differ between the plants cultured under both conditions. 17. The number of streaming root hairs in rice plant decreased under pH 4.0 and over pH 10.4, in wellwater. The streaming stopped completely at pH 1.4 as the result of coagulation of the protoplasm. At pH 10.5 the protoplasm of all root hairs dissolved. 18. [the rest omitted]

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1. The growth of roots of rice seedlings are inhibited as the concentration of (NH₄)₂SO₄ in wellwater increases. The inhibiting effect of (NH₄)₂SO₄ is less in the "Shinriki" variety (high yield and susceptible to rice blast) as compared to the "Kameji" variety (low yield and insusceptible to rice blast) in wellwater as well as in nutrient solution with the pH controlled at 5.5 or 7.0. 2. High concentration of (NH₄)₂SO₄ which inhibits the growth of roots also inhibits the protoplasmic streaming in root hairs. The rate of streaming increases somewhat in adequately diluted solution (0.001 mol) of (NH₄)₂SO₄ which was also found to be the optimum concentration for top growth. 3. When pH values of wellwater are distinctly low, the growth of roots and protoplasmic streaming are inhibited with the effects being less in the "Shinriki" variety as compared to the "Kameji" variety.

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1. Microscopic measurements showed that the stomatal apertures were narrower in their size for three days suice the harming had been enforced on wheat leaves. The fact confirmes the inducton, reported formerly by the authors, that the increased loss of water caused by the treatment brought on a reduced state of turgor, and which resulted those characteristics of the stamped plants. 2. When the stamping had been enforced at the n-th stage of seedlings, the(n+1)th leaves were effected mostly showing shortening of the length and increase of the stomatal index, in accordance with the anatomical observation which indicated that the differentiation of the stomatal cells had been occured on the leaves of ca. 6 mm length, and those length were seen in the next leaves to the uppermost ones in the fall sown wheat seedlings. 3. A lowering in the accumulation of carbohydrates, which is attributed to the hindrance of translocation from the leaf blades to the growing points by the bending of stems or leaves, and suggested in the former reports as one of the causes of the retardation of spikelet differentiation in the treated plants, was certified by the results of chemical analysis. Broken tissue of vascular bundles and its mending took in a while were observed under microscope at the bent portion of blade.

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Rice-stem-borer (Chilo simplex Butler), the most serious harmful insect in Japan, prospers in this region, especially in her first generation rather than in her second generation, as compared with other regions. Special attention must be paid, therefore, to the control of this insect in her first generation. In this respect, we analyse the problem into several points, varietal resistance, cultivation system, and the insect habits such as egg-laying, larvae intrusion and the course of spreading the damage spheres. In this report, the cause of varietal difference of egg-laying freqnency by rice-stem-borer was investigated and some important reason of attracting borer-moth to rice-plant was detected. (1) Among varieties a definite tendeny was observed in regard to the frequency of egg-laying on rice-plant, including several nursery conditions of different levels of application of nitrogenous fertilizer. (2) It was recognized that varieties on which more egg-batches were layed, exudated larger quantity of dew drops on the edges of leaf-blades, the dew drops being larger or more quickly formed. The quantity of exudation was studied more precisely in every one hour throughout the night by gathering drops with injecters. It was observed that the number of egg-batches layed, is closely related with the quantity of exudation at night, especially in the forenight. And it was ascertained that the exudation contained a small quantity of ammonia. (3) It was supposed that borer-moth is attracted to rice-plant, in the main, chemotactically; the exudation of leaf-blades containing some substances which attract the moth and, further, the substances will be some N-compounds.

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(1) Newly hatched larvae were set on leaf-blades of seedlings of various varieties of different ages, and the behavior of larvae, position of intrusion and plant character were investigated in the laboratory. (2) Many larvae set on leaf-blades creep generally upward seeking the spot to bore and some larvae hung themselves from the top of leaf-blade spitting the yarn. But the majority of larvae soon creep down again, wandering about the ligules and auricles, and at last come to near the surface of water. Then larvae crecp a little way upward again, and begin to bore. It needs usually long time (about one hour) to seek the spot to bore, but very short time from boring till intrusion. (3) In genral, the openings of intrusion located on some definite position of leaf-sheath, namely on the lower part of younger seedlings and upper part of aged seedlings. And the openings were found on the parenchymatous parts between each vascular bundle near the midrib, especially on the wider part than the breadth of the larvae head. (4) The percentage of the intruded larvae into the tissue or of the remainder found ontside the plant, showed the grade of resistance of plant against intrusion. This grade was fairly different among varieties and also markedly varied in accordance with the age of seedling. (5) Generally speaking, larvae did not gnaw at the part of vascular bundles. The loci of gnawing had no relation with the width of the parenchymatous parts, but the openings of intrusion were generally found on the wider part of parenchymatous parts than the breadth of the larval head. Among varieties the correlation between the percentage of the intruded larvae and the width of intervascular parenchymatous parts was fairly close. (6) Thus we can come to the conclusion that the width of the parenchymatous parts of intervascular bundles of the leaf-sheath is one of the chief factors to decide the grade of resistance of plant against larvae intrusion.

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(1) Five incubated egg-batches were inoculated on rice-plant of various varieties in the field, and the occurence of the incipient by borers were investigated. (2) The damages occured within the narrow range on the lee-ward of inoculation centre. (3) The percentage of the damaged tillers of 6 hills within 2∼3 feet afar, the figures being adjusted by the damages of contorol (non-inoculated) plot, expressed clearly the grade of the damages. (4) The grade of the damages are correlated both with the "cover degree" of varieties and also with the grade of resistance of plant against larvae intrusion. (5) This relation will be affirmed on the Figure 2.

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1. It has been cleary shown by Prof. T. Morinaga that three Species of genus Panax. viz. P. ginseng, P. quiquefolia, and P. japonicum f. typicum have all 24 chromosomes in their gametic numbers, and there are no special differences in shape among bivalents at meiosis of those three species. These points were confirmed again in the present studies. 2. At meiosis, the pollen mother cells of the F₁ hybrids, P. ginseng × P. quinquefolia, and P. japonicum f. typicum × P. quinquefolia, showed in most cases, metaphasic configuration presented as 23_II+2_I, though rarely 22_II+4_I was also found. In the F₁ hybrids, P. ginseng × P. japonicum f. typicum, the metaphasic configuration was 22_II+4_I in most cases, and 21_II+6_I and 20_II+8_I were also met with rather frequently. 3. From the results above mentioned, it is concluded that the genomes of those species belong to genus Panax are essentially identical, though some differentiation seems to have occurred between the genomes of those different species. The degrees of the differentiation are rather low between those of P. ginseng and P. quinquefolia, and P. quinquefolia and P. japonicum f. typicum, between those of P. ginseng and P. japonicum f. typicum, however, the differentiation seems to be somewhat higher.

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