The annual fluctuation of growth of sand eel collected from 1968 to 1977 was studied in relation to the population density in Ise Bay. There was no apparent sex difference in the growth in the first and second years of life. The population was divided into two groups, age 0 and 1 groups, based on the distribution of body length. Biweekly mean body length and mean body weight for each year-class remarkably fluctuated every year. A considerable yearly variation occurring in the growth was in close connection with the fluctuation of population density of age 0 group. A highly significant negative correlation existed between the growth in weight and the population density.
The efficiency of biomass production of Escherichia coli and the nitrogen balance of the aerobic culture system were studied in a nitrogen-limited medium where glutamic acid or ammonium sulfate was the sole source of nitrogen. The amount of bacterial-N at the stationary pbase was proportional to the amount of nitrogen added to the medium, and most of the nitrogen consumed was converted into cell material while a small amount was excreted as waste products. Chemical properties of the nitrogen in the waste products were affected both by the carbon source and by the pH of the medium. The dynamic equilibrium of nitrogen between the bacterium and the waste products was also discussed from the active reutilization of nitrogen in the waste products by the same bacterium.
The association-analysis of WILLIAMS and LAMBERT was applied to the vegetation of the dune system at Azigaura, Ibaraki Pref. Four types of associations were recognized and their relations with edaphic environments were investigated. The association characterized by Carex kobomugi and Carystegia soldanella was situated on the fore dunes near the sea and its soil had a large amount of exchangeable cations. The second association containing Ischaemum antephoroides, Glehnia littoralis, Zoysia macrostachya, Oenothera erythrosepala, etc. occurred on the semi-fixed dunes. The vegetation on sandy hillocks and well drained grasslands was divided as the third association. It was dominated by Indigofera pseudo-tinctoria associated with Erigeron canadensis and E. sumatrensis. Its habitat was characterized by higt organic matter and nutrient content. The fourth association defined by the presence or Erigeron annuus was situated on slacks and low-lying wet regions and characterized by high soil moisture.
At six different places in Kagoshima city and its vicinity, the leaf longevity of Euonymus japonicus was investigated between 1972 and 1976,in relation to the number of blister-like leaf galls produced by Masakimyia pustulae. Because the ungalled or lightly galled leaves were seldom shed except in the emergence seasons of the new leaves, stepwise survival curves of the leaves were obtained in seminatural environments. In urban environments, the mean leaf longevity was distinctly shorter than that in natural or seminatural environments. The mean longevity of the heavily galled leaves was considerably shortened in both the seminatural and urban environments. Particularly in the latter environments, the heavily galled leaves suffered from anthracnose disease, (caused by Gloeosporium euonymicolum), more severely than those in the former. Such an earlier fall of leaves was considered to operate as a density dependent mortality factor upon the urban populations of M. pustulae, which is univoltine and inhabits the leaf galls throughout the larval and pupal stages.
Pattern of habitat utilization, home range and food habits of a raccoon dog are studied in a small islet, Takashima, western Kyushu. The home range and the number of individuals in the area are established by means of a bait-marking method which is a new technique developed in this study taking notice of the peculiar behaviour or the raccoon dog to defecate its feces daily on a definite fecal pile site. The size of home range estimated by the method ranged from 1.1 to 4.3 ha (2.8 ha av.) and the total number of individuals in this islet was 8.6-16.1,0.46-0.86 per ha in density. The individual home ranges overlapped closely to each in four seasons. The small population size and high population density in this islet are explained by the confined circumstances of habitat in the one hand and by the specific modes of life of the raccoon dog, that they can live together in a small area with cooperative utilization of the habitat on the other.
Hatching in Gampsoleis buergeri was synchronized neither in continuous darkness nor in continuous light at any temperature. However, it occurred synchronously at around sunrise under natural light conditions at about 24℃, and also at around lights-on in an artificial photoperiod of 12-hr light : 12-hr dark at temperatures between 15 and 25℃. The hatching in thermoperiods (12-hr warm phase : 12-hr cool phase) was concentrated at 8-10 hr after the temperature down in continuous darkness but spread over the entire cool phase in continuous light. Hatching was also synchronized by a single light-dark shift, a temperature down or a high temperature pulse in otherwise constant conditions. when eggs were transferred from cyclical to constant external conditions, the daily rhythm of hatching disappeared almost at once. It seems, therefore, that any circadian oscillator is not explicitly involved in the determination of hatching time. The direct response to a single stimulus of light or temperature was different between G.buergeri and Metrioptera hime, but in other respects their responses were similar, which suggest that they share the same basic system of time measurement.
Communities of oribatid mites in 7 different organic substances were investigated in the forest of Pinus densiflora at Mt.Fujisan, Central Japan. The seven representative substances consisted of many kinds of plant debris and moss; i.e. (1) litter, (2) fermentation and humus layers, (3) fallen twigs, (4) fallen cones, (5) upper layer of soil, (6) moss growing on rocks, and (7) moss growing on rotten woods. Different degrees of similarity (tested by the JACCARD's coefficient and the WHITTAKER'S percentage similarity) were found among the oribatid fauna of various kinds of organic substaces. Dominant species in most of the substances consisted of very common species such as Oppiella nova or Tectocepheus velatus, but the most dominant species on fallen cones was Hypochthoniella minutissima.
Litsea japonia scrubs develop confinedly along San'in coast with the eastern and northern limits at Mihonoseki, Shimane Peninsula, and at Goka, Oki Island respectively. The Litsea scrub is conspicuous on the side facing the Japan Sea, and it is confronted with Quercus phillyraeoides scrub on the side of the Pacific Ocean exclusively. Macroclimatically, the distribution of the Litsea scrub on the coast of the Japan Sea was explained from the effect of the winter-monsoon. Low temperatures and the desiccation brought about by the winter-monsoon from Asian continent may be the limiting factor for its limited distribution along San'in coast. Suzuki's index devised for charactcrizing the climate of the area facing the Japan Sea coincided well with the distribution of the scrub less than 90 of the value.
On the windward slope of the Shirouma Mountain Region there exist alpine desert plant communities extensively. The areas of the plant communities form extensive deblis fields. However, the distrlbution of these plant communities is confined in the areas of rhyolite and serpentinite. To clarify the factors controlling the distribution or these plant communities. cryopedogenic processes and debris supply were examined.