This investigation was carried out in order to confirm the existence of rooting inhibitors the cuttings of Pinus densiflora.
Outline of experimental results are as follows:
Both the acid and neutral fractions of ether extrats obtained from the shoots which are used as cuttings, of Pinus densiflora inhibited rooting of cuttings of Populus nigra.,
Salix graciilistyla and Amorpha fruticosa.
The growth inhibitors were found, but no growth stimulators in the acid and neutral fractions of ether extracts.
From these results, it may be considered that rooting inhiditors exist in the cuttings of Pinus densflora and they are related the growth inhhibibitors.
These experiments were carried out in January 1961.

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Recent researches of the writer's showed that, if placed under certain treatments, cuttings of pine were successfully rooted be ca. 50%, especially by ca. 70% in the case of those planted on Oct. 20, 1960
The following are the results of these researches made with the cuttings of red pine
Pinus densiflora.
1) Materials and methods
The cuttings were collected from many mother trees 10_??_12 years old, and then were planted in Kanuma-soil bed that had been prepared in a shadeless glass-house.
The cuttings were cut 3_??_4 cm below the bases of the top buds, and their cut surfaces were treated with IBA in talc paste, 10 mg/g.
The medium was kept at 20_??_23°C by bottom heater.
2) Experimental results a. The cuttings showed higher percentage of rooting on the medium kept at 20_??_23°C than on the not-heated medium,
b. The cuttings which had been treated with IBA and NAA showed the greatest percentage of rooting, especially those planted on Sept. 7, reaching 60% of rooting and those planted on Oct 20, ca. 700%.
The IBA treatments was significant in 5% level.
This shows that it is very important for cuttngs of red pine.
c. The cuttings were collected from both ordinary and regenerated branches.
The former showed 50% of rooting and the latter 30% of rooting.
d. The cuttings which have more buds have a tendency to produce more roots when they take root.

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Comparisions between the traditional procedure and Prof. Ogihara-revised procedure in the application of Noetzli's theory to the designing of arch dams are made on an actual example of an arch dam, especially in the light of their provided degrees of deflections equalization between the two systems, as well as with regard to their calculated stress diagrams.
Also discussed is the often proposed question of the height of the water-pressure-proportioning point versus the thickness of the dam base, in an effort to constitute a practical criterion to the designing of arch dams. Concluded are:
(1) The revised procedure of water-pressure proportioning is more recommendable, as opposed to the the traditional one, for its effecting a higher-degree equalization of deflections and for its faster and easier calculating
(2) a=Ø(B_oⁿ), or the height of the water-pressure-proportioning point increases with an increased dam-base thickness; When, for example, the value of “a” exceeds the crown height of the dam, the thickness is due to be reduced, so that the water-pressure proportioning might not minister to an irrationally excessive cost of the dam construction.

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[in Japanese]

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The fundamental unit of Acacia mollissima bark tannin is suggested to be 3, 7, 3', 4', 5'-pentahydroxy-2-phenyl chroman by Roux. This tannin is supposed to be a mixture of polymes formed by condensation of the above unit. In this investgation, the collagen colum chromatographic method is applied for the fractionation of the polymer in the Acacia mollissima bark tannin. And the determination of the molecular weight, the acetyl value as well as the content of carbon and hydrogen of each fraction is carried out. As a result, it has been found that the tannin is mainly composed of 5 to 6 units of 3, 7, 3', 4', 5'-pentahydroxy-2-phenyl chroman.

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