Sounds of the wing beat of 31 insect species were tape-recorded to analyse their wave types with an oscilloscope. The frequency of wing beat ranged between 250 and 350Hz. The differences in the wave type among various insect species were more remarkable than those in the frequency of wing beat. The waves observed in the oscilloscope were interpreted to represent the mode of vibration, but not the tone, of the wing sound. Vibration of the wings of Aedes joponicus, Armigeres rubolbatus, and Promachus yezonicus showed smooth sin curves in the oscilloscope, while that of Nilaparvata lugens presented a remarkable zigzag curve. For each of the other species species-specific curve was obtained.

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An easier method for counting and estimating the number of individuals on the assumption that the number of individuals in each quadrat changes according to Poisson or negative binomial distribution is derived in this paper, and here frequency distributions having more than 2 classes are dealt with. The method for calculating the estimator (i.e. the population size) by using the maximum likelihood is derived. Also the number of quadrats required to obtain an estimate as precise as the complete counts is given in tabular form. Application of the method is illustrated by using sampling data of an aphid population.

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The color and shape of the sporodochia and perithecia were investigated in 31 strains of the redheaded scale fungi which form sporodochia on the body surfaces of 21 species of scale insects. All of the sporodochia were orange-red and varied in shape. These stains could not be separated on the basis of color and shape of the sporodochia. Only 2 strains which were found on Lepidosaphes tubulorum FERRIS and Pseudaulacaspis pentagona TARGIONI formed perithecia, which were of the Nectria type. The macro-conidia, produced in Sabouraud dextrose agar of single isolates, were measured for size and were examined for the number of septa and their shapes. These characters did not differ among strains except for one strain. The fungus strain, which was isolated from Pseudaonidia paeoniae COCKERELL, formed distinctly small macro-conidia. The observations indicated that all, except one strain, should be reduced to one species, Nectria episphaeria (TODE) SNYDER et HANSEN. The exceptional strain was identified as Fusarium nivale SNYDER et HANSEN.

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Optically active acetotriglycerides were isolated from the lipids of a scale insect, Icerya purchasi. The hydrogenated Icerya acetotriglycerides gave a plain, negative opticalrotatory dispersion curve. Comparison of the triglycerides with those of known configuration in the optical-rotatory behavior showed that the Icerya acetotriglycerides were essentially (S)-1, 2-diacyl-3-acetin. The constituent acetotriglyceride acids, other than acetic, were ordinary long-chain fatty acids. Stearic, oleic and linoleic acids were present in abundance in the 2-position.

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The formation of a red fluorescent protein (RFP), an anti-viral substance present in the digestive juice, was studied in “in vitro” system. The RFP was produced by incubating the mixture of the homogenate of the midgut and the chloroplast of spinach leaves for 2hr (37°C, pH 10.4). The midgut was obtained from 5th instar larvae which had been reared on an artificial diet. An active protein was isolated from the midgut of the larvae and two active substances, chlorophyll a and a basic protein, were obtained from the chloroplast of the spinach. The RFP was produced by incubating the mixture of these three pure active components in the same alkaline state as mentioned above. It was highly probable that the protein from the midgut was the protein-part of the RFP and the basic protein from the spinach was an enzyme which converts chlorophyll a into the pigment-part of the RFP.

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A small flacherie virus (SFV) was isolated from a regular flacherie virus (FV) in the diseased silkworm larvae and partially purified. Then, silkworm larvae were inoculated per os by feeding the SFV suspension on the mulberry leaves. On the 7th day after inoculation, the infected larvae were dissected out and their tissues were processed for the optical and electron microscope histopathology. The optical microscope observations revealed that the infected nuclei of columnar cells had swollen and contained a few inclusions which were stained intensely with Feulgen. In other cells, such as goblet cells of the midgut, fat cells and epidermal cells, no remarkable histopathological changes were observed. It was demonstrated by electron microscope observations that the virogenic stroma where SFV particles were produced were formed in the nuclei of columnar cells. Although SFV multiplied independently of FV multiplication in the columnar cell, it was frequently observed that SFV and FV infected doubly in a columnar cell, the former in the nucleus was about 19nm in diameter and the latter in the cytoplasm was about 25nm in diameter. From the results, it was suggested that SFV is a virus species different from FV.

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The age of Ursus arctos yesoensis was known to be determined by teeth annuli, but the number and clarity of annuli sometimes differed from bear to bear or between the different kinds of teeth obtained from the same individual. In order to examine the characteristics of teeth annuli, 2 bears of known age (No.5 and 7) and 6 bears of unknown age were employed. The age of the bears of unknown was estimated by examining J₁ and P₄ teeth, which exhibited clear annuli. The teeth of J₁, J₂, J₃, C, P₁, P₄, M₁, M₂ and M₃ of the lower jaw obtained from No.7 bear and some others were analyzed for detecting morphological and numerical differences of annuli. The age estimated from the annuli of C was sometimes younger than the actual age by one year due probably to the delayed development of the canine. The annuli numbers observed in the other kind of teeth coincided with one another (Fig. 9-17). There were 2 assertions that in the first one, the annuli formed in the period before the hibernation, and that in another, it begun to form in the fall and completed in April or May of the next year. In No.1 (11 years and 8 months) bear which was killed at the end of September, J₁ showed 11 annuli in the inner part of the cementum, and the marginal cement layer was unstained. However, a little stained short line was found in it, indicating a new annulus formation (Fig. 1). P₄ of No.2 (3y. & 9m.) bear which was killed in early October showed almost the same feature of new annulus formation as that of No.1 (Fig. 2). J₁ of No.3 (14y. & 10m.) bear which was killed at the end of November had 15 annuli, of which the outmost one was stained faintly (Fig. 3). J₁ of No.4 (2y. & 10m.) bear which was killed at the end of November showed about the same features as that of J₁ of No.3 (Fig. 4). P₄ of No.5 (5y. & 1m.) bear which was killed in the middle of Feburuary had 5 distinct annuli, and the outmost annulus was clear and perfect (Fig. 5). J₁ of No.6 (11y. & 2m.) bear which was killed at the end of March had 11 clear annuli, and an unstained cementum layer was developing on the outer side of the outmost annulus (Fig. 6). P₄ of No.7 (5y. & 3m.) bear which was killed in the middle of April showed 5 dark stained annuli, and an unstained cementum layer developed in some extent (Fig. 7). J₁ of No.8 (10y. & 4m.) bear which was killed at the beginning of May showed 10 annuli with a well developed marginal unstained cementum layer (Fig. 8). It was clear that the formation of new annulus began in the middle of September and continued up to the end of April. The No.5 bear was castrated male, so that it was suggested that the sex hormone had no relation to the annuli formation (Fig. 24). In this species the so-called accessory lines appeared, which closely resembled annuli and were also reported in grazzly bear. Therefore, in such a case, several kinds of teeth should be examined for an exact age determination. The mechanism of the accessory line formation and its significance are not known at present.

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