Kitayama polished log is an useful lumber for construction materials of japaneue arxhitecture produced from North-west district of Kyoto city, and is one race of sugi (Cryptmeria japonica D. Don.). This wood is restrained from growth by frequent pruning for special purpose during its growing period. This experiment was attempted to research the superiority in strength properties of Kitayama-sugi. The results obtained by this test are as follows.
(1) Compression strength: Kitayama-sugi is stronger 18-30% than normal sugi.
(2) Beding strength: Kitayama-sugi is stronger 56-62% in bending strength and larger 10-43% in Young's Modulus than normal sugi.
(3) Impact bending work: Kitayama-sugi is larger 54-114% than normal sugi.
(4) The relations between density of annual rings and specific gravity, between density of annual rings and summer wood percentage are shown in fig. 1.
(5) The relations between density of annual rings and bending strength, between density of annual rings and Young's Modulus are shown in fig. 2.
(6) The relations between summer wood percentage and bending strength, between summer wood percentage and Young's Modulus are shown in fig. 3.

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1. This research was hold on Aleurites Fordii and Sapium sebiferum, having purpose to study the relation between the thickness of sowing and the growth of seedling. And it is a part of investigation on the sylviculture of economic trees of special use.
2. The research was carried out at nursery of Saikyo Universisy; from May, 1949 to January, 1950. After this, we are going to observe the growth of seedling after transplantation, continually.
3. The standing thickness of seedlings are thinner than the sowing thickness because of practical germination percent showed 46% (Aleurites) and 27% (Sapium). Then in this research, 60 seedlings which are standards of every sections, were selected.
4. The result of this research tells that the growth of Aleuriles Fordii is best at V section, but IV section showed the nearest growth to V, too. Therefore, from the productive point of view per unit area; 25 grains per m² is considered the most suitable.
5. Sapium sebiferum showed best result at E section, but from the same meaning with above mentioned considered that D section (100 grains per m²) is the most suitable.
6. This research is the comparison of growth of seedling when the germination percent of both tree kinds are about 50_??_60% (estimated). It is a matter of course that increase or decrease of germination percent brings about some change of suitable sowing thickness.

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This repport is the result of comparison among the variation of Pinus densiflora SIEB. et ZUCC, needle. The experimental trees are 23 years old and 8 9 monthes old: the former are planted in the museum garden of Kyoto University (Kamigamo, Kyoto), and the latter are planted in the nursery of Saikyo University (Simogamo, Kyoto). The summary of results are follows.
1. The experimental seeds are collected from 31 districts, in Japan. As a tentative plan, we divided them into 12 locality, as Fig. 1.
2. The external morphological comparison of needles showed on the Table 1. and Fig. 2.
3. The variation of resin ducts in needle are compared on the middle part cross-section. Fig. 3. shows the 12 forms of resin ducts: I type are originally belonged Pinus Thunbergii PABL., and P. densiflora normaly has only II or III type. And yet the result of the research, like Table 2, several sections, show the tendency to P. Thunbergii.
4. The interspecies hybrid.between P. densiflora and P. Thunbergii has been already known, but by the result of our research, we have to think that the hybrids exist more than we have thought. (cf. Table 4.)
5. The relation between development of resin duct and the resistance to the harm of Coleoptera is an interesting problem.
But we have had yet no data to solve it.
6. As Table 3, in 24 years old part, the number of stoma is abundant in north-east part of Japan, decrease south-west.
It is considerd, that the number of stoma has some relation to the climate, especially moisture. But we have yet no completed data.
7. After all the Local-races Landsorten of Cryptomeria japonica D. DON are well known, but of Pinns densiflora are not yet made clear. However as above-mentioned, from the result of our research; Pinus densiflora has some common characters among different districts.

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1. It is the idea about the equipment with the double winding drum winch by reconstructing some part of the wood gas internal combustion Locomotive for the logging railroad.
2. It is the point to chain one more pinion gear to the bevele gear of the reversing gear, and then to be worked continuously to the winch driven shaft.
3. We could increase efficiency of the work for clearing, loading and piling by this reconstruction of equipment as the double winding drum winch that has movement nature except faculty as the Locomotive.
4. We have effects of this reconstruction Locomotive at the National Forest of Takanosu and Aniai Divisional Forest Office.

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In 1936, one of us (ONAKA) reported beforehand that the enzymatically-produced cavities appeared occasionally in the secondary walls of tracheids of coniferous wood-fragments taken from the ancient tombs or remains, and that the cavities disposed parallel to the micellar arrangement. Now we have made studies of the micellar arrangement of “Ichii”-(Taxus cuspidata S. et Z.), Hinoki-(Chamaecyparis obtusa S. et Z.), “Koyamaki” (Sciadopitys verticillata S. et Z.) and “Konotegashiwa”- (Thuja orientalis Carr.) woods of the same kinds.
The results obtained are as follows:
1. Micells in the secondary walls of a coniferous tracheid arrange nearly at a certain angle to the axis of the cell forming a single spiral around it. But thir arrangement do not pass over the pits.
2. Concerning one tracheid, the inclination of the micellar arrangement to the cell axis is rather less at the both ends of it than at the center, and the matter is same on tangential wall where the diameter of tracheids is smaller because of contact with the ray.
3. In springwood, the inclination of the micellar arrangement on tangetial walls is rather less than on radial, but in summerwood it is contrary.
4. Though th e inclination of the micellar arrangement in summerwood is generally rather les than in springwood, the difference is not so evident on tangential as on radial walls.
5. On radial walls the diameter of tracheids become naturally small towards summerwood from spring-one and the inclination of the micellar arrangement has also similar tendency. And the correlation of both is positive and high. But on tangential' walls it is not so evident.

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We must decide the form of shot specimen, when study the compressive strength of bamboo piece.
This study is made on the optimum height-thickness ratio (h/a) and width-thickness ratio (b/a) of specimen in the test of compressive strength parallel with the grain of small clear specimen, by mean of investigating the maximum crushing strength and types of failure that occur in the test on MA-DAKE, MOSO-CHIKU and HA-CHIKU.
The results and conclusion of this study are following.
(1) The compressive strength of bamboo piece is not influenced by b/a, but decrease with decreasing h/a lineally. (See Fig. 2) Therefore there is not optimum form of specimen in the test of compressive strength parallel with the grain.
(2) The appearance-rate of normal type (type “b”) of failure, in the test of compressive strength parallel with the grain, is maximum at b/a=1.0_??_1.5 and h/a=2.0_??_2.5. (see Fig. 3b, 3a)
(3) Author concluded that the optimum form of small, clear and short specimen in the test of compressive strength parallel with the grain of bamboo piece is b/a=1 and h/a=2.

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This experiment has the objects to study on the preserving power of pine root oil. This is a principal constituent of preservative which is prepared in the WOOD RESEARCH INSTITUTE, KYOTO UNIVERSITY.
And then at same time we tested the preserving power of coal-tar, hinori oil, and two sorts of pine root heavy oil mixed sulfurous turpentin oil.
1. On the “Kuromatsu” (Pinus Thunbergii) which is painted with pine root oil, the rate of decrease in compressive strength is 1.2%, and “the staying ratio”^* is 1.17 times of unpainted wood. On the wood which is painted with coal-tar, the rate of decrease is 4.6%, and “the staying ratio” is 1.12.
2. On the “Kuri” (Castanea crenata) which is painted with pine root oil, the rate of decrease is 2.2%, and “the staying ratio” is 1.28 On the wood which is painted with coal-tar, the rate of decrease is 9.8%, and “the staying ratio” is 1.19.
3. As well, on the “Hinoki” (Chamaecyparis obtusa) which is painted with pine root oil, the rate of decrease is 0.0%, and “the staying ratio” is 1.20. On the wood which is painted with coal-tar, the rate of decrease is 2.8%, and “the staying ratio” is 1.15.
4. The reason that the pine root oil has the greatest preserving power on these three sorts of wood is the following.
Cresol fraction which has great strilizing power is existent in 175_??_240°C distillate of pine root oil, i.e., middle oil.
It seems that the middle oil is useful in the preserving action of pine root oil.

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