1. Young peach seedlings were planted in four tree rows in sandy loam soil orchard. Alternate two rows of trees were mulched with 3kg of straw per tree on July 4 and remaining two rows were clean cultured. Thereafter soil moisture in 20, 60 and 120cm depth and total length of top growth were measured about every 10 days and top and root fresh weight and root distribution were investigated.
2. The difference of soil moisture, below the 20 cm depth, by the soil managements was less than that of soil moisture by location. Since be-ginning of August, a month after mulching, total top growth in mulched plots was supeAor to that of clean cultured and on September total length of top growth in every tree row mulched was longer than that of clean cultured.
3. Top and root fresh weight were heavier in mulched plots than clean cultured. Root distribut ion of mulched plots was especially greater in depth of 0_??_10cm. Fine root less than 1mm in diameter distributed chiefly in 0_??_10cm depth in mulched plots and 10_??_20cm in clean cultured. The root distribution between the 20 and 60cm depth was not so different as to distinguish the difference of surface soil managements. But the roots of mulched trees penetrated deeply and the fresh weight of roots below 60cm depth was more than that of clean cultured.
The present results seems to point to the good penetration of roots by the vigorous tree growth notwithstanding of abundant shallow root distribution in surface soil. The difference of soil moisture about 10cm deep was not measured but the effects of mulching on the soil moisture, under present soil condition, seemed to be limited within only 20cm depth of surface soil.

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Quite different opinions about which will be discussed later have been proposed by three wor-kers, with regard to the behavior of incompatible pollen in Brassica oleracea (SASAOKA 1928, KAKIZAKI 1930, and SEARS 1937). The situation makes this plant of particular interest for pollen tube studies. In order to elucidate this problem the writer has attempted some experiments with cabbges and cauliflowers. In these investigations the following varieties were used as material :
Cabbage; Nozaki-Wase, Nakano-Wase, and Succession.
Cauliflower; Gokuwase, and Gokuwase-Taikyu. Both self- and cross-pollinations were made simultaneously on the same plant. In these ex-periments the pistils were collected at intervals, killed in acetic-alcohol, slit with a razor blade lengthwise into three sections, and stained with 0.5 percent lactic blue for about 2 hours. After being differentiated in lactic acid for about 24 hours, mounts were made in a drop of glycerine. Sufficient pressure was applied to the cover glass to squeeze the style into a thin layer only two or three cells in thickness. The results obtained are summarized as follows:
I. Brassica oleracea L. var capitata L.
In self-pollinated flowers, a few of the pollen grains _ were found on the stigmas. It is thought that most of the pollen grains which failed to germinate had been washed off in the treatment of fixing and staining. The germination of pollen was decreased. Pollen tubes usually ceased to develop when they were about as long as the diameter of a pollen grain, and failed to penetrate into the stigma. Some tubes coiled around the papillae. Emptied pollen grains were scarcely found which had emptied their contents into their tubes. Nozaki-Wase, No. 7 was an only exception, which may probably be a self-compatible plant (Table 1). Consequently, the behavior of incompatible pollen was found to be similar to that of the broccoli by SEARS (1937). It may be concluded that the self-incompatibility of the cabbage is attributed to decreased germination of incompatible pollen and to no penetration of tubes into the stigma.
On the behavior of pollen after cross-pollination, there was a clear distinction between incompatible and compatible matings. 1) In cross-incompatible combinations, the behavior was found to be quite similar to that of incompatible pollen after self- pollination. 2) In cross-compatible matings, nu-merous pollen grains were found on the stigmas, the percentage of pollen germinated being much higher than that of self-pollination. A high proportion of emptied pollen grains was obtained. The tissue of the style wsa penetrated freely by pollen tubes. The longest tube reached the ovary in about 8 hours after pollination. Numerous pollen tubes could be found in the style and ovary in about 24 hours after pollination (Table 2).
When a long time had passed after self-pol-lination, the percentage of pollen germinated was increased, and only a few emptied grains were also found, even in incompatible flowers (Table 3). This phenomenon might be explained more reasonably by assuming of the rendering com-patible of incompatible pollen in long time inter-vals after self-pollination, than by assuming that pollen germination and tube growth were very slow after self-pollination. This idea might be supported by the fact that the pollen viability of the cabbage was maintained satisfactorily for 7 days at 11°C (PEARSON 1933), and by the fact that cabbage flowers selfed 2 or 3 days after open-ing gave much better seed production than those selfed on the same day when flowers opened, namely, the secretion of inhibiting substance that prevents self-fertilization might be decreased in the old pistils (KAKIZAKI 1930, MOHAMMAD 1935, and SIIINOHARA 1942)

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(1) In the previous report, the authors had proved that the number of sweet potato tubers per sprout were certainly increased by soaking the sprout in synthetic growth substance (pota-ssium α-naphthaleneacetate). The study reported here were successively carried out in 1945-47.
(2) The growth hormone was significantly effective on increasing tuber numbers on the various sprouts, except on very small and tender ones, and these were especially remarkable for the hard ones. On the sprout having small leaf area, the effect was also observed.
(3) In every case, the hormones-like effect (tuber increasing effect), can be observed by water soaking treatment, and because these effects were distinguished from those of hor-mone by shortening the time of the treatment, it seems that these were due to quick root deve-looment, by absorbing water.
(4) The effect of the growth hormone treatment on increasing tuber numbers was also observed on the comparatively dried or high nitrogen level fields, but were not especially remarkable as compared with ordinary ones.
(5) When the growth hormone or the watersoaking treatment was effective on increasing the tuber numbers, the length of the tuber necks were shortened and this fact was especially remarkable under the dry condition of the field. This fact seems to denote that by hormone or water treatments, root tuber formation was smoothly occured and cork formation of root tissues were delayed.
(6) Why the numbers of the tuber were increased by hormone treatment? We consi-dered the following reasons, A. Acceleration of root formation. B. To increase the number of roots. C. Cork formation of root tissues were delayed.
Above facts show from nutritional condition of sprout that the nutrient of sprout (stored and elaborated) might be translocated to roots predominantly.
(7) The effect of the treated solution on the root numbers in the early stage of the tuber growth was tested with the seven varieties. The results show that 0.002% solution was most effective for four varieties, 0.005% was for two, 0.0005% was for one.
(8) Effects of the hormone treatment on the tuber yield, were almost insigni fi cant, so we can not discuss statistically and it seems that the growth hormone treatment did not necessarily cause increasing of the root tuber yield.

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1. Influences of temperature and sugar concentration of the germinating bed upon the pollen tube development and growth of the easter lily were investigated.
2. The optimum temperature for the pollen tube development is recognised to be about 30°C and when lowered to 11°C they cannot develop their tubes, in 40°C on the other hand, most of them will burst in a few hours and if some others may germinate their tube growths are almost impossible.
3. The optimum sugar concentration for the pollen tube development is ascertained to be about 8% and though they can germinate freely in a wide range of 2-16% their germinating percentages and tube growths gradually decrease.
4. Pollen tube developments on the stigma are considered to be much the same in both cases of self pollination and cross pollination, but in the former the rapidity of the pollen tube growth in the stylar cavity is a half of the latter for the first 24-40 hours after pollination and when they have travelled down about one half to two thirds of the whole length of the style, most of tubes are arrested decidedly.

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This study was performed to know the influence of high temperature on the flowering and setting of pods in kidney bean. The varieties tested were Kurozuru and Kisasage.
1. The temperature had a strong influence on the setting of pods and ripenning of seeds in kidney bean. The correlation coefficient of set percentage and temperature at 10 a. m. were as follows:-
runner type γ=-0.699 P<0.001
dwarf type γ=-0, 739 P<0.001
2. There were three stages of flower abscission in runner type, i. e., early stage, middle stage, and late stage.
3. It was expected that the flower abscission of early stage was due to shortage of nutrient by spending to plant development.
4. Flower abscission of middle stage would be owing to competition of nutrient among flowers.
5. Flower abscission of the late stage was consi-dered to be due to the decline of plant and the influence of high temperature.

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