The author has put forth efforts to make clear the influences exerted by the treatments of rice plants with sodium chloride or sea-water, upon the germination force under saline water and some biochemical characters of the seeds obtained therefrom. The results may be summarized as follows: 1) Treatments of rice plants with saline water exerted injurious influences upon their growth and yield, and greater influences were caused according to the strength of salinity. When treated at their tillering stage or ear-forming stage, the plants suffered much greater injury, bringing about much smaller yield. Especially the weight of one grain showed a remarkable fall through the treatment at the latter stage. 2) It can be considered that the germination under saline water of the seeds thus obtained varied much more with the stages at which the treatments had been carried out than with the concentrations of NaCl with which the parent plants had been treated. And especially the treatment from the heading stage to the maturing stage exerted a greater influence upon the germination of the seeds thus obtained, while the weights of seeds seemed to have little connection with the germination under saline water and the growth of seedlings. 3) The embryos of the hulled rice yielded through the above treatments came to have a greater TTC reducing activity, and the paper-electrophoretic patterns of protein in the hulled rice in question were somewhat different from those of the others. 4) Judging from these results, the activity of the enzymes in the seeds obtained through the above treatments seemed to have changed its degree, which caused the seeds to show the singularly, in their germination under saline water.

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The effects of BCB on the growth, cell division, and cell elongation of wheat, lowland rice, potato, and tobacco plants were studied. Treatment was consisted of one application of 250 ml of BCB solution at the concentration from 10^-2 M to 10^-4 M, poured into the soil of each 1/5000 are Wagner's pot. In the wheat, the leaf length was shortened and the leaf color became greener by BCB-treatment. Except the case of 10^-2M concentration, the mumber of tillers increased and the emergence of tillers and leaves was accelerated in the treated plants. In the lowland rice seedlings, the growth of leaves, unless being sowed thickly, was not affected by BCB-treatment so much as wheat, but the number of tillers increased and the emergence of tillers and leaves was accelerated after transplantation. The stem elongation of potato was inhibited and more lateral shootings, greener and crapier leaves were observed in case of soil or seed treatment. But the horizontal development of leaves scarcely decreased, and the wet weight of the top or leaves increased slightly. In the tobacco seedlings, the growth of stem and leaves was affected like that of potato and the leaf development was hastened by applying BCB solution at 1/5×10^-2M. From histological observation on the treated plants, it was attributed to the inhibition of cell division and cell elongation that the leaf area and stem length were reduced by BCB-treatment. The ability of cell devision in the subapical meristem of tobacco stems treated with BCB was lowered, and the length of subapical meristematic zone was shortened like that of chrysanthemum treated with Amo-1618.

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1. Studies were made on the habit of pod setting, and on the cause and mechanism of pod shedding of A. Manihot. 2. There were no differences between two varieties used in this experiment on the set % of pod. 3. The set % of pod in the plants with artifical pollination was higher than that in the plants with natural pollination in the victorial lawm, owing to the structure of flower. 4. The set % of pod in the plants with open pollination was higher than that in the artificially self pollinated plants. This was owing to the structure of flower and the highly developed abscission layers. 5. When the lateral shoot was put off the set % of pod in the main stem was high, though the number of pod was small. 6. he set % of pod was correlated with the stage of plant growth and the environment, showing the higher % in early and late stage than in middle one and under the state of comparatively low temperature and high moisture than otherwise.

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1) In order to obtain some fundamental informations for potato cultivation, the responses under various combinations of plant spacing, amounts of fertilizer and number of stem per tuber were investigated by using two varieties. 2) The dry-weight of top per hill increased proportionnally with the increase of the spacing-area of one plant. However, the larger the spacing-area is, the longer the time is taken to reach a given yield per unit area, thus the plants continuing the vegetative growth for a long time. Consequently, the tuber yields per unit area increased in proportion to the decrease of the spacing-area. 3) Factors influencing the tuber yields per unit area varied with the branching habits of potato varieties used. For Danshaku-imo (Irish Cobbler), a mild branching variety, the increase of either fertilizers or number of stem per tuber brought high yields as spacing of hills increased. While, for Norin No. 1, a highly branching variety, the increase of both fertilizers and number of stem per tuber was necessary to get high yields. 4) Four growth types were classified based on the difference between two parts of the stem which were divided at the 1st flower cluster, and it was found that there is a close relation between the growth type and the tuber yields, and there exists favourable growth type expecting high yields. 5) It was concluded that the regulation of the growth of potatoes by the combinations of spacing of hills, amounts of fertilizer and number of stem per tuber should be changed with the ecological characteristics of the varieties used.

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When rice plants are supplied with a large amount of fertilizer, especially of nitrogenous one, increase in grain yield is not always proportional to the amount of applied manure, the response being different from variety to variety. The fact has been explained as the difference in "varietal adaptability for heavy manuring". According to Baba, three different characteristics of rice plant, namely, resistance to disease (rice blast), resistance to lodging, and morphological and physiological characteristics, are concerned with this adaptability. On considering the third characteristics, which are believed to, be associated with the adaptability in narrower meaning, we meet with two fundamental problems of different category: The first is how the pattern of dry matter production will be influenced, and the second is what changes will be brought about in the distribution or translocation of the matter produced, under heavily manured conditions. It is regarding the first problem that we have intended to carry out a series of experiments, in which the meaturement of photosynthesis and respiration, both under field and laboratory conditions, and of other plant factors concerning the dry matter production in the field were included. The present paper reports the results of experiments using the following six, medium-maturing varieties which are different in their adaptability for heavy manuring: Hokuriku No. 52 (most suitable for heavy manuring), Norin No. 25 (suitable), Yamakogane (suitable), Kiyosumi (less suitable), Chiba-asahi (less suitable), and Tamanishiki (least suitable). These were cultured on the paddy field under normal and double nitrogen supply. The results obtained may be summarized as follows: (1) The rate of promotion in the photosynthetic capacity, on field area basis, of the heavily fertilized plot to the normally fertilized plot was greater in varieties more suitable for heavy manuring than in less suitable ones. However, the rate of promotion in respiration, also on field area basis, was greater in less suitable varieties. The ratio, therefore, of photosynthetic capacity to respiration rate (P/R), which may be regarded as an index of efficiency in dry matter production, was higher in more suitable varieties than less suitable ones, when nitrogen was abundantly supplied. (2) The P/R ratio can be analysed into four factors; photosynthetic activity of unit leaf area (p₀), respiration rate of unit dry matter (r), light-receiving coefficient (f), and leaf area ratio (LAR), in the following way: As there exists the following equation among P, f, p₀ and the total leaf area (A), according to our previous work (Murata et al., 1957), P=Afp₀, the P/R ratio can be transformed into, P/R=fp₀A/rW=fp₀/r=A/W=fp₀/rLAR where W and r stand for the total dry weight of the plant, and its per unit respiratory activity, respectively. Through almost all the varieties used, it was found that by increasing nitrogen supply those varieties suitable for heavy manuring were more promoted or improved in their unit photosynthetic activity, LAR, and efficiency in receiving light, but not so much in their unit respiration rate, as compared wtih less suitable varieties. It was concluded that the P/R ratio was determined by the composit effect of all these changes in the four factors and it was suggested that varieties more suitable for heavy manuring can produce dry matter more efficiently than less suitable ones in the field under heavy manuring.

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In six early-maturing rice varieties, Fujiminori (suitable for heavy manuring), Fujisaka No. 5 (suitable), Akibae (a little suitable), Norin No. 1 (less suitable), Obanazawa No. 1 (least suitable), and Kamenoo (least suitable), which were cultured on the paddy field under normal and double nitrogen levels, it was shown that the ratio of photosynthetic capacity to respiration (P/R), both on field area basis, had an intimate relationship with the adaptability for heavy manuring, the more suitable the higher the ratio. This is in good accordance with our previous results on medium varieties. Moreover, the following facts were observed by investigating the four factors which compose the P/R ratio: (1) Photosynthetic activity on unit leaf area was higher in the varieties less suitable for heavy manuring, just reverse to the case of medium varieties. However, (2) respiration rate of unit dry matter was higher in less suitable varieties in accordance with medium varieties. (3) While the plant shape of less suitable varieties under normal nitrogen supply was rather unfavorable for receiving light efficiently in comparison to suitable ones, it became comparatively favorable under heavy nitrogen supply, considering its greater increase in total leaf area. (4) There was no definite relationship found between LAR and the adaptability. From these it was deduced that the above-mentioned changes in the ratio brought about by heavy nitrogen supply were chiefly caused by changes in the second factor, namely the respiratory activity. Summing up the results of both early and medium varieties, it may be concluded as follows: In both maturing varieties, from the view point of efficiency in dry matter production, the varietal adaptability in rice for heavy manuring has a close relationship with the P/R ratio which represents a composite efficiency in dry matter production of rice plants as a whole. However, early and medium varieties showed the following differences in the relationship: In medium varieties, the adaptability had a correlation with the P/R ratio not in its absolute value but in its rate of change due to high nitrogen supply, whereas in early varieties, the correlation was seen regardless of the level of nitrogen supply. In the case of early varieties, therefore, it is not the "adaptability for heavy manuring" itself but the "high yielding ability" that has a substantial correlation with the varietal response for manuring. When the grain yield is considered from two phases, namely dry matter production and its translocation, it may be said that in medium varieties, the P/R ratio is directly associated with the "adaptability" in the former phase, whereas in early varieties, it has a relationship with the "adaptability" only in broader meaning similar to the "high yielding ability". It may be possible, therefore, that in early varieties a definite relationship is to be found in the latter phase, namely in the translocation phase, between physiological characteristics and the "adaptability for heavy manuring".

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From the date of flowering to the full ripening stage, the developmental processes were studied at natural, 20°C and 30°C constant conditions. At 20°C, in comparison with the natural condition, the rate of development was same in Stages I-IV (from the division of endosperm mother nucleus to the stage of the peripheral cell layer formation), slightly quicker in Stages V-XI (from the stage of filling up of the embryosac cavity with endosperm cells to the stage of beginning of cell maturation) and was very slow in the last Stages XII-XIII (completion of cell growth and constriction of tissue). At 30°C, the developmental processes were hastened by 1.5∼2 times than that at 20°C, and finally reached the last Stage XIII on the 23rd day after anthesis. Among three temperature conditions, there were no differences in the number of endosperm cells. Hence, it may be said that the division of the endosperm cells, that is, the increase of the cells in number is independent of the temperature. However, at high temperature, the growth of the cells were hindered and the cells were smaller in size though they matured. At 30°C, the reserve starch grains began to deposit in the endosperm cells about 2∼3 days earlier than in the case of 20°C and of the natural condition. But at 30°C, the first type of starch grains found to be slightly smaller in size, and that the second type of starch grains appeared to be remarkably scantier in number than in the case of natural condition. There were no remarkable differences in the development of the starch grains between 20°C and natural condition. The above observations indicate that the temperature has a influence on the maturation of the endosperm cells, and that especially high temperature shortens the time in the ripening stages. Besides, the high temperature hastens the withering of the assimilate organs, and all leaves were already withering up in 19 days after anthesis at 30°C. Therefore, it may bring the decrease of the reserve substances which were supposed to be transported into the ear. Consequently, the seeds riped at 30°C were very thin in shape and light in weight. It was an interesting fact that the temperature affected not only the grain weight, size, color and protein content, but also the shape of the endosperm cells and size and number of the starch gains which were closely related to the quality of the flour and its taste.

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The experiment was carried out with variety "Ginmasari" as early season rice culture, and with variety "Kinmaze" as early planting rice culture on the well-drained paddy field of alluvial loam, in 1960. The field was divided into two blocks each differing in depth of tillage and the amount of applied cattle stable manure, with the other. As chemical fertilizer, fused magnesium phosphate and potasium chloride were added as basic dressing, without any nitrogen. To one block which was ploughed to a depth of 25 cm, manure was applied at the rate of 9 tons/10 a (0.1 ha), while the other block ploughed to a depth of 50 cm was applied at the rate of 15 tons/10 a. Besides, planting was carried out according to the following density, having 70, 105 hills, each of which consisting of 3 and 5 seedlings, and 140 hills which consisting of 4 and 7 seedlings per tsubo (3.3m²), respecitively. The result is summarized as follows: 1. During the early part of July, the period between the stage of the maximum number of tillers and the booting stage of variety "Ginmasari", and between the late stage of tillering and the stage of the maximum number of tillers of variety "Kinmaze", the rice plant showed nutrition deficiency which increased remarkably with increasing plant density. This is assumed to indicate that reasonable heavy application of manure is rational in the case of rice culture under the conditions of deep tillage, and dense planting. This phenomenon, however, got naturally disappeared after the end of July, and the rice plant of the block of 50 cm depth tillage showed growth responses indicating the existence of excessive nutrition during the ripening stage after September. 2. The yield of brown rice per 10a showed generally high production varing propo tionately to the increase of planting density; from 566∼606 kg with variety "Ginmasari" and 588∼664 kg with variety "Kinmaze" of the block of 25 cm depth tillage, and 584∼661 kg of the block of 50 cm depth tillage with variety "Kinmaze" respectively. The ratio of increasing yield to increasing plant density was low in variety "Ginmasari", and high in the case of "Kinmaze". 3. The increase of yield to increasing plant density was mainly due to the increase of total number of grains with the increase of number of panicles. The ratio of the weight of fine-husked rice to the weight of coarse-unhusked rice did not give any evidence to recognize the difference among the different planting density plots. 4. In comparing the two depth tillage blocks of the variety "Kinmaze", the block of 50cm depth tillage had a high total number of unhusked grains, and a low ratio of the weight of fine-husked rice to the weight of coarse unhusked rice.

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It has been considered that silica is one of the factors which influence the adaptability of rice plant for heavy manuring. In this paper, the influence of silica on the adaptability for heavy manuring of rice plant was investigated in particular with regard to photosynthesis. Experiment was carried out using aggregate plants which were solution-cultured under four combinations of nitrogen and silica supply. Results obtained were as follows: 1. At heading stage, high supply of silica increased the leaf area and the photosynthetic capacity of the plants as a whole, and decreased their respiration (Table 3, 4 and Fig. 2). Such an effect of silica was greater at high nitrogen level than low level. 2. High silica supply also brought about slight decrease of photosynthetic activity on unit leaf area (Table 3). However, the ratio of unit photosynthesis to respiration was greater in high silica plot than in lower one, because of the greater decrease of unit respiration rate in the former plot (Table 3). 3. The plants supplied with sufficient silica showed an improvement in their form of assimilation system as to be able to receive light with higher efficiency than the plants of less silica supply (Table 4). The improvement may, it was found, mainly in that the leaves attached to the stem at more acute angle and that the leaves themselves were less curved and thick (Table 5). 4. From the above results it may be concluded that, by the application of sufficient silica, the low efficiency, in dry matter production, which is invitable with those plants grown too much luxuriantly as an aggregate under heavy nitrogen supply, can be improved to some extent and, as a result, the overall adaptability of the plants for heavy manuring can be increased.

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1) The sterile phenomenom in wheat plants caused by the low temperature, that is one type of the chilling injuries, has been found almost every year at Sigarami region, Nagano prefecture. The present report deals with some researches on the sterile phenomenon in relation to the mechanism of its occurrence. 2) From the results obtained, it may be said that the sterile phenomenon is not caused by insects, mineral defficiencies and nutritional conditions of the plant, but is caused by such a meterological condition as the grass temperature is about 0∼3°C. It seems that a sensitive stage for the low temperature injury is the just before the earing and is a definite stage of the pollen development, the stage of the pollen first nuclear division. 3) The probability of the occurrence of the sterile phenomenon can be considered to be very high when the wheat plants arrived at that stage of pollen development just meet with the low temperature mentioned above.

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Considering from the spikelet arrangement on panicle of rice plant, paddy or rice kernel may have two different flanks, i.e. abaxial side and adaxial side. The differences in these two sides were investigated mainly upon shape, hardness and ripening of the kernels of three rice varieties (Norin-6, Norin-8 and Fujisaka-5). The results and discussion are summarized as follows: 1) In many cases, both dorsal and ventral ridges of the paddy or kernel were seen indented towards the adaxial sides. And on both flower glumes and kernel of very young dry paddy, some-what crescent shapes with their adaxial sides concaved were observed on the cross section. 2) When observed on the cross section, each of the flanks of kernel has two protuberant parts: one close to the dorsal region and another close to ventral region. And the dorso-adaxial and ventro-abaxial protuberances were considerably biased towards dorsal and ventral sections respectively, showing well development of starch tissues in these parts. Above all, the most remarkable growth of tissues was seen around the dorso-adaxial region, so that the distortion of kernel was also clear as observed from the base or top of kernel. 3) Of young kernel, the vascular bundle was seen exactly on the dorsal ridge. But the ridge of mature kernel was formed frequently biasing a little to the abaxial side of the bundle, presumably on account of an extensional growth of tissue prevailing around the dorso-abaxial region. 4) Distortion in the dorsal part was first seen in the kernels of early ripening stage, and it became more distinct in the older kernels. On the other hand, the ventral distortion seemed to occur about 10 to 15 days after flowering. 5) Completion of ripening which was investigated by observing degree of translucency especially in the peripheral starch tissues of kernel proceded was earlier in the adaxial side than in the opposite side. 6) Results of hardness tests conducted on cross sections of kernel with a Vickers micro-hardness tester revealed that the region around the center was much harder than the periphery, and moreover that the adaxial region was harder than the abaxial region to some extent. It is presumed that the biased shape of flower glumes and unbalanced kernel growth incur the distortion of the kernel, which become clearer with the advance of maturation and is featured especially by the well growing of dorso-adaxial region, and that the adaxial region of kernel as a whole is superior to the opposite region in the ability of starch filling in the middle to late stages of ripening.

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The petiole-girdled leaves of soybean plants, which have been placed for a short period of time in the nitrogen deficient solution, exhibited continual decrease in protein with corresponding increase in soluble nitrogenous compounds. Translocation of these soluble nitrogenous compounds through the girdle was found to be almost entirely disturbed, as total nitrogen content (expressed as leaf area basis) in the leaves plus petioles (portions above the girdle) were little changed throughout the experimental period. About half the nitrogen liberated by protein degradation in the petiole-girdled leaves appearred in the petiole portions above the girdle, and there, fair amount of the migrated nitrogen was elaborated into petiole proteins. Pteiole-girdled leaves, which have been deprived of exogenous nitrogen sources, recovered the ability of synthesizing and maintaining protein only when nitrogen was added exogenously to the plants. The results of chemical analysis as well as the facts mentioned above suggested that newly added nitrogen may have been better available for new protein synthesis than soluble nitrogen that had been retained in the petiole-girdled leaves.

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In order to clarify the function of leaves in soybeans, growth and constituents in each leaf were examined every two weeks. The results obtained are as follows: 1) The leaves expanded about 10 days after the emergence of the leaves and grew large for two weeks after that period. The length of upper leaves were commonly larger than the lower ones, however, several ones at tips became smaller. 2) The content of nutrients in each leaf increased as growing and became largest at the period of about one week after when the length of leaves became largest, and after that period decreased gradually. The changes of the content of nutrients had almost same tendency between leaves, however, were not volumetrically. 3) The life of lower leaves was shorter than the upper ones and the almost constant life after the emergence of the branch from the definite section was observed in lower leaves. The primary and the 1st leaf are connected deeply with the early growth and the other lower leaves with the branching. 4) The upper leaves had longer life than the lower ones, had pretty long duration of high nutrient contents and had close relationships with the flowering and the fruiting.

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The interaction of BCB and gibberellin was investigated in potato, wheat, and kidney bean (long variety) plants. In the potato, 250 ml of 10^-2 or 10^-3 M BCB solution was soaked into the soil in a 1/5000 are Wagner's pot, and gibberellin solution at a concentration of 10, 1, or 0.1 p.p.m was sprayed three times. As a result, BCB inhibited the stem elongation and gibberellin accelerated it, and an antagonism between BCB and gibberellin was observed. In the wheat, 250 ml of 1/2×10^-2 or 10^-3 M BCB solution and gibberellin at a concentration of 10 or 1 p.p.m. were applied in the same way as the dosage for potato plants. BCB shortened the leaf length and increased the number of tillers, but gibberellin elongated the leaf and did not increase the number of tillers, and an antagonism between both chemicals was observed. In the kidney bean, 180 ml of 10^-2, 1/2×10^-2, or 10^-3 M BCB solution was soaked into the soil in a 7 inches clay pot, and gibberellin at a concentration of 10, 1, or 0.1 p.p.m. was sprayed two times. As a result, the stems treated with 10^-2M BCB failed to elongate, and gibberellin removed the inhibition by BCB.

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Lowland rice var Norin No. 29, Norin No. 21, Ginmasari, Fujisaka No. 5, and Obanasawa No. 1 were cultured under various levels of nitrogen and the relationship between nitrogen supply and grain production was examined. The results obtained are summarized as follows: Under low level of nitrogen, grain yield increases remarkably with increment of nitrogen supply, though, the rate of yield increment diminishes as the nitrogen supply increases. After certain limit, additional supply of nitrogen does not increase grain production, but decreases it conversely. Such aspect of fertilizer response is based mainly on the phenonmenon of "diminishing return" in dry matter production of ripening period. Under high level of nitrogen, development of leaves is very vigorous in vegetative period and consequently the total leaf area becomes so large that the photosynthetic ability of plant itself is high during the period of ripening. But, at the same time, luxurience of leaves results in heavy mutual shading and consequently inhibits the photosynthetic activities to a certain extent under the community condition. Therefore, actual rate of photosynthesis is not so high as it is expected from the size of the leaf area. Respiratory ability of plant, on the other hand, also rises remarkably with increment of nitrogen supply. In the case of respiration, however, inhibition by mutual shading does not take place, as this physiological process does not require sun light. Therefore, under high level of nitrogen, production process (photosynthesis) is partially inhibited, whereas consumption process (respiration) is not affected. Consequently, net gain of plant decreases under such condition. This is the physiological base of the phenonmenon of diminishing return in dry matter production of ripening period and in grain yield, because major portion of the matter produced is accumulated in the grain at the ripening period. Rarely, a factor other than dry matter production causes the tendency of diminishing return in the yield of the grain. In the case, where weather condition is strikingly bad at the time of flowering, process of fertilization suffers inhibition. The inhibition of fertilization increases with the increment of nitrogen supply, and as a result number of fertilized spikelets decrease after a certain limit of nitrogen supply. Under such a special condition, yield of grain is limited rather by the mumber of fertilized spikelets than by the amount of material to be accumulated in it. Under usual conditions, with the increment of nitrogen supply, the number of fertilized grain increases at a higher rate than the amount of material to be accumulated in it. Therefore amount of material to be collected in individual grain decreases with the increment of nitrogen supply. This results in decrease in the thickness of individual grain.

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Various size and forms of vessel members, parenchyma cells, and fibers were found in roots, leaves and stems of rice plants. The primary walls of protoxylem vessels in leaves and stems were always found destroyed, so it was not made possible to observe their size. The metaxylem vessels of each organ were divided into two types according to length and diameter of their elements; some were longer having smaller diameters (metaxylem I) while others were shorter with larger diameters (metaxylem II). Out of all wood elements, fibers in each organ were the longest with smallest diameters sometimes having wave-like roughness on their surface. In the nodes of stems, various forms of metaxylem vessels with many perforations were found. By the observation on leaves it is assumed that the vessels of connecting tissues are composed of elements of metaxylem. In the protoxylem of each organ, two types of thickening were found, that is annular and spiral. In leaves and stems, especially the wall of annular elements thickens conspicuously. On the contrary, in roots, the thickening of both these two types of elements is less. In the metaxylem I, many types of thickening were observed. In leaves, annular and spiral elements are dominant. In roots and stems besides these, scalariform and pitted ones could also be observed. In the metaxylem II, the type of thickening of vessel elements differs in different organs. In leaves, a kind of scalariform elements is most common. In roots, on the contrary, the most common type of thickening found is pitted. In stems, the thickening shows the intermediate type between those found in roots and leaves. The parenchyma and fiber cells of xylem also show thickening in their cell walls. The walls of fibers are pitted with the pits distributed sparsely. On the walls of parenchyma cells, much variation in the type of thickening was observed. It sometimes resembles that of vessels and sometimes that of fibers. The perforation plate of metaxylem II can be divided into several types, that is, simple transverse, simple oblique, scalariform and tracheid-like. The former two are commonly found in rice plants. But in the shoot, especially in leaves, the latter types are frequenty observed. It is assumed from these observations that the roots are evolutionally the most advanced and the leaves the most primitive organs of the plant.

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In the case of root injuried, it was observed that protein breakdown occurred with rapid decrease of RNA in the shoots of rice plant (from the previous report). Accordingly, author considers that RNA metabolism of the roots played an inportant role im nitrogen metabolism of the shoots. In this experiment, RNA synthesis in the root was inhibited by soaking the root in ribonuclease solution. Results obtained are as follow: (1) The content of protein-nitrogen decreased with the increase of soluble-nitrogen and this tendency attained maximum at the concentration of 500 ppm RNase. (2) The ratio of protein-N/soluble-N fell with the lapse of time, and soluble-nitrogen attained maximum at the 8th day after treatments and then decreased. (3) The rate of growth in the term of fresh weight was greatly retarded by RNase-treatment during the 8 days. After that, this tendency was disappeared and the growth of the shoot recovered. (4) As regards the relationship between roots and shoots, it was observed that elongation of the newly developing leaf was largely affected by the treatments of rots, and with the cessation of the treatments, new roots developed so quickly that new leaf began to appear. This fact suggests that there is close relationship between development of new roots and formation of new leaves.

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