In these experiments, a chain saw was driven by electric dynamometer with constant speed of 10.5 m/s at the tip of teeth and a timber with uniform diameter of 36cm was cut across. In this case, power necessary for cutting, time elapsed from the first to each section of the timber, normal force between teeth and the timber etc. were measured respecting to four kinds of teeth. As a result, three factors weree proposed to show the cutting performance of a chain saw.

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Yasushi SUZUKI: Distribution of several strength values and specific gravity in bamboo culm (Phyllostachys pubescens MAGEL et H.DE LEHAIE).
An attmpt is made to inquired each distribution of several strength values and specific gravity in bamboo culm (Phyllostachys pubescens MAGEL et H.DE LEHAIE). It is clear from the experimental results that specific gravity and any mechanical strengths are higher at outer or upper part than inner or lower part respectively. The nodes are high in specific gravity, shearing strength, and low in bending strength, compared with the internodes.

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Kamekichi YAZAWA: Researches on the relation of heartwood-diameter and perce-ntage sapwood to log-diameter for sugi (Cryptomeria japonica D. Don) in Nara and Miyazaki Prefecture.
1) The following equations represent the relation between the log-diameter (D: sun) and the heartwood-diameter (d: sun) for sugi: for sugi in Nara Prefecture............d=-1.8873+0.9355 D for sugi in Miyazaki Prefecture...........d=-2.3294+0.9647 D
2) Correlation coefficients between log-diameter and heartwood-diameter for sugi are as follows:
for sugi in Nara Prefecture............r=+0.9995±0.0002
for sugi in Miyazaki Prefecture............r=+0.9993±0.0004
3) In a given log-diameter, the heartwood-diameter of sugi is smaller than that of most of other species of coniferous wood growing in Japan excepting Japanese red pine.

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The developments of callus and adventitious roots were studied in cuttings of epicotylic shoots of akamatu (Pinus densiflora) seedlings, and the new shoots of modoomatu (so-called natural hybrid of P. densiflora×P. Thunbergii). which have developed from decapitated epicotyls of one year old seedlings.
At first, callus develop from the cambium and the phloemoand then, from the cortex near the phloem, and from the pith. In callus, irregular xylem tissues, which are accompanied by-cambium and phloem to its outer surface, develop in connection with the newly formed xylem of the stem.
Roots appear at first as the protuberances of callus, and seem to be exogenous in their origin. More detailed developing processes should be examined.

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1. Change in the rate of water absorption of shoots of Cryptomeria japonica when exposbd to wind was measured by potometer in experimental room conditions.
2. It needed an adjustment period before the steady absorption rate conditioned by wind was attained, and there could be found three types in the phange of absorption rate of that period, i.e., the initial rate before steady rate for wind is (a) higher than, (b) equal to, and (c) lower than the latter.
3. Among these three types, , type-(a) occurred more frequently with lower water contents and higher absorption rate for calm air conditions, type-(c) with conditions reverse to (a), and type-(b) with intermediate of other two.
4. These three types are supposed as resulting from the difference in the resistance to the transmission of effects of water deficit from transpiring leaves to absorbing surface, which is conditioned by the water relations in plant body.
The writer is grateful to PROF. DR. NAKAMURA KENTARO^* for his guidance and criticism during this study, and also to Ass. PROF. M. ONSI MASAMI^* for his kindness in reading the original manuscript.

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