Two kinds of cocoons with different properties were reeled in three different sizes, 21, 27 and 31 denier, by the automatic reeling machine which was used for the cocoon certification to observe the occurrence times of both dropping and feeding ends.
The occurrence of dropping ends between two consecutive events of feeding ends could approximately be regarded as a Poisson process. Since it seemed difficult to discuss the distribution of the interval of dropping ends in the fixed size reeling theoretically, indirect discussion was given by obtaining the probability density function of that interval in the reeling with fixed number of cocoons.
To evaluate the decrease in the size of raw silk caused by dropping ends, the sizes of 200-300 cocoon filaments were measured when they dropped in reeling by counter reel. The results showed that the last sizes of cocoon filaments could be approximated by log-normal distribution.

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Stochastic structure was discussed with respect to the decrease of the size of raw silk caused by dropping ends and the characteristic function expressing its stochastic structure was presented.
Variation of the size of raw silk except for the parts of dropping ends and feeding ends was approximated by a WIENER process with drift, and parameters of this process were related with the property of cocoon.
Connecting above two processes, a complete stochastic model of the variation of the size of raw silk was formulated.
Estimates of the parameters were obtained from the experimental results.

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[in Japanese]

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[in Japanese]

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The larvae of two oily mutant strains, og ang og^t, and the oily larvae of F₁ hybrid between og and og^t strains were used for the determination of xanthine dehydrogenase (XDH) activity and the amount of purine compounds.
1. XDH activity was considerably high in the normal larval and adults, but almost negligible in all of the three mutant larvae and adults employed.
2. The feces and integument of the normal larval contained a large amount of uric acid, but only a small amount of xanthine. On the other hand, there existed a large amount of both hypoxanthine and xanthine or one of them in the feces, blood, and meconium of the og^t mutant, but no uric acid was detected. A small amount of uric acid was found in the feces and integument of the og and og^t/og mutants, whereas there was a large amount of either hypoxanthine or xanthine in their feces and meconium.
The present results indicate that the og gene induces the deficiency of XDH. Thus, it is evident that the suppression of the formation of uric acid results in the transparent larval skin of the three mutant strains.

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The dry weight of mucous gland of the newly emerged female adult was approximately 6-9mg. On the other hand, the weight of glutinous substance, secreted from the gland and adhering on eggs, was about 16-24mg. This fact suggests that glutious substance is synthesized even during the period of egg deposition. This was confirmed by measuring the rate of incorporation of ¹⁴C-1-glycine into the mucous gland. It was found that glutinous substance was vigorously synthesized during the oviposition, and that some glutinous substance was formed even after the completion of oviposition.
The major amino acids of glutinous substance were glutamic acid, glycine and aspartic acid, which were contained at levels of 16.8, 13.9 and 11.3 mole %, respectively. On the other hand, sulfur-containing amino acids and glucosamine were contained in a very small quantity, being less than 1 mole %. When the protein of the glutinous substance was analyzed by SDS-acrylamide gel electrophoresis, highly reproducible pattern of bands was obtained. It was consisted of 9 major and 8 minor bands, and the molecular weights of the major components were estimated to be between 9900 to 76000, respectively.

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The gut content decreased markedly during the first two days after pupation, and kept a low level thereafter. On the other hand, the rectum content which began to accumulate on the fifth day of pupation increased linearly as the pupal development proceeded until the adult emergence, especially in the male. The meconium of the male moth was over 2.7 times as much as that of the female.
Analysis of the free amino acid of the meconium showed that histidine was contained at the highest concentration, followed by tryptophan and arginine. Furthermore, cystathionine and lysine were contained at considerably high levels.
From the investigation of the histidine degradation by means of histidine-¹⁴C (U), it was found that histidine injected into pupae was slightly recovered in respired CO₂ at the level as low as 0.009%, and that most of the injected histidine-¹⁴C was discharged into the meconium. Furthermore, the scanning of radioactivity on thin-layer chromatogram of the meconium revealed that histidine-¹⁴C was scarcely converted to other metabolites.

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This work was undertaken to determine the phosphorylase activity in various larval tissues of the silkworm, Bombyx mori., and the results obtained were summarized as follows:
The phosphorylase activity in the homogenate of fat body was measured in the direction of glycogen breakdown with a coupled assay system with reduction of NADP in the presence of added G-6-P dehydrogenase. The effect of different concentrations of glycogen, inorganic phosphate, and 5′-AMP on the enzyme activity was studied.
The activity of phosphorylase a and b in larval tissues was determined in the presence or the absence of added 5′-AMP; phosphorylase b required 0.7mM of 5′-AMP for the maximum activity and 0.2mM for half as much as the maximum activity.
The activity of phosphorylase a and b and the ratio of a-type activity to the total activity was varied considerably according to the type of tissues used. In the middle stage of the 5th instar the ratios of a-type were 50, 75, and 30%, in the midgut, muscle and fat body, respectively. In the fat body the ratio of a-type was as high as 70% just after the 4th ecdysis, but then lowered to 30% in the latter half of the 5th instar.
The ratio of a-type was gradually elevated in both the midgut and the fat body during starvation but returned to the original ratio after feeding.

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Phosphorylase a and b were isolated from the larval fat body of the silkworm, Bombyx mori, and the enzymatic properties of phosphorylase b were studied. The results obtained were summarized as follows:
Two peaks of phosphorylase activity were detected by the elution chromatography on DEAE-cellulose column. By the addition of 5′-AMP peak I was greatly activated, whereas peak II was not altered at all. Peak I and II were, therefore, identified as phosphorylase b and a, respectively.
The optimal pH for phosphorylase b activity was around pH 7.5. The half-maximal point of phosporylase b activation was reached when 1.1-1.6mM of 5′-AMP was added.
Values of apparent Km for glycogen ranged from 0.14 to 0.56mM and were remarkably dependent on the concentration of phosphate in the reaction mixture.
Double reciprocal plots of velocity and phosphate concentration were not observed to be linear.
The activation of phosphorylase b by 5′-AMP was competitively inhibited by the addition of 5′-GMP.

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The pigments in the eggs of a serosa color mutant, re (red), of the silkworm were analyzed by paper chromatography. Three fractions were separated, that is, orange (Or2), yellow (Ye2) and brown (Br) ones. Or2 fraction was supposed to be xanthommatin. Although Br fraction was not identified, it was supposed to be a compound(s) closely related to ommatin D. Br fraction degraded gradually with time under acid conditions and the degradation products were Or2 (xanthommatin) and Ye2 fractions.

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The phytotoxicity of a herbicide, simazine, to mulberry plants, and its effects on the dry matter budget of the plants were investigated and the following results were obtained.
The treatment with 10^-4M simazine per kg of dry soil resulted in only slight or no phytotoxicity. However, the treatment with 10^-2M simazine per kg of dry soil inhibited the development of new leaves, and gave rise to chlorosis and necrosis of the mulberry leaves that had already developed before the treatment, leading to the occurrence of fallen leaves.
The treatment with 10^-4M simazine per kg of dry soil reduced the photosynthesis and the respiration in the mulberry leaves, and their chlorophyll, sugar and starch contents were also decreased. However, photosynthesis, respiration and chlorophyll content were restored in about 5 days. The treatment with a higher concentration of simazine resulted in decreases in these parameters, followed by no restoration to normal.

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Heavy metal pollution of mulberry plants in the vicinity of zinc refineries in Annaka, Japan, was investigated.
1. Even today when the exhaust gas treating facilities have been greatly improved, the mulberry plants in the vicinity of the refineries are still polluted with heavy metals, especially with cadmium and zinc. The closer the mulberry field to the refineries, the heavier the pollution. The pollution was heavier in October than in July. However, the pollution was considerably less than that reported by KOBAYASHI et al., who had investigated the same district before the exhaust gas treating facilities were improved.
2. Heavy metal pollution, when classed by the leaf order, tended to be higher in the leaves in the lower order, especially in October.
3. In the mulberry fields where the soil was heavilly polluted and acidified, there were virtually no small roots of mulberry plants distributed in the soil layer up to 30cm bellow the ground.

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[in Japanese]

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