The secondary succession in the grassland of the Utsukuahigahara Heights (ca. 2000 m above sealevel), was investigated by using permanent quadrats set on May 31,1959 at 3 areas, covered respectively with thicker (area 2), mean (area 1) or thinner (area 3) snow during the winter. Each of these areas consisted of 3 experimental sections : the grassland protected from treading, the bare-ground newly prepared within the protected one, and the unprotected grassland. In 1969,the vegetation of the bare-ground (area 2) recovered to almost the previous condition. In area 1 and 3,however, the central zone of the bare-ground remained as it was, and only its peripheral zone was covered with grasses. In both the protected and unprotected grasslands, the vegetation was simplified due to the number of plant species reduced from year to year. The unprotected grassland was characterized by a considerable decrease of herbs coverage.
Newly hatched larvae of the pond smelt tend to be distributed in the deeper layer of the profoundal region of Lake Suwa, probably after being carried by the inflow of the river where the hatchery is located. They begin to migrate with growth towards the sublittoral region. The succession of food organisms eaten by the larval and young pond smelts in the lake can be indicated as follows : rotifers (pro-larva and early post-larva)→copepod nauplii (early post-larva)→Bomsina and Mesocyclops (post-larva and young fish)→Leptodora and Diaphanosoma (young fish). Observations of cultured larvae in a glass aquarium showed that the larvae up to a body length of 11 mm or more caught their food by a darting movement produced by a S-shaped flexure of the body and those up to 16 mm or more swam in one or more schools gathering each other. In appendix, the relation of the progress of eutrophication in the lake to the annual catches of the pond smelt in the course of the recent thirteen years is discussed.
There is a resemblance between Taraxacum officinale and Youngia japonica in that they have two peaks of flowering. Youngia japonica in the district may be said to be a perennial herb which scarcely withers after flowering. In Aster subulatus, there are some perennial individuals of which the stembases remain after flowering and then bud next spring. Although Galinsoga parviflora somewhat declines in number of individuals in winter, it germinates, grows, blooms, and bears fruit throughout the year. Chrysanthemum indicum and Aster hispidus are seen till about March at the seaside districts. Some of the latter are perennial. The author made clear, in this paper, the attachable term of mature seeds on several wild herbs, which had never been reported.
In another paper, the author reported on the food items of wild Japanese black bears, analysed from their stomach-contents and feces. The present paper deals with some calorimetric consideration of the food of the animcal in wild state and in zoos. Each food item from the stomach-contents was newly collected in the field and measured by a bomb calorimeter. The results are shown in Table 1,and the total sustaining calories of each stomach content can be accumulated, as shown in Table 2. The largest value is 2200 kcal. It may be estimated that under the digestion-and absorption-rate is 50 percent, one satiety in a wild bear involves about 1000 kcal nutrition. On the other hand, baits for the animal in zoos contain 4536 kcal a day, as shown in Table 3,and a wild bear requires at least 4000 kcal inthe author's view. In Japan, the cutting of the natural forest, causing the lack of foods for the bear, makes it hunger and drives the animal to damage farm crops.
Dormant one-year-old twigs of about 60 tree species were collected from mature trees growing in different altitudes on Yakushima Island in early January. Evergreen broad-leaf trees growing in the low altitudes below 200 m above sea level, resisted freezing between -3 and -15℃, with the exception of Ficus retusa and Kandella Candel. Most of the tree species growing near the top of Mt. Taichu (1511 m) resisted freezing to -20℃. Three species, Sorbus commixta, Pieris japonica, Rhododendron Metternichii survived freezing down to -25℃ or below. Abies firma collected at about 1200 m altitude was hardy to about -25℃. This fir was found to be nearly as hardy as those of the northern boundary of its natural ranges, Fukushima Prefecture. A similar trend was observed in most of the evergreen broad-leaf trees from between Yakushima Island and Ibaraki Prefecture. However, slight intraspecific differences were observed in the freezing resistance among the evergreen broad-leaf and coniferous trees tested. These differences generally appeared to be closelv related to the winter coldness of their native habitats.
Population dynamics of the regional population of the Japanese macaques at Ryozenyama were studied from the point of view of demography. Most males, perhaps all, left their original troop, mainly between 4 and 6 years old. Sexual interaction with females of the troop was maintained by males who came from outside the troop. Even females with her offspring occasionally left the troop and some of them may have delivered the young outside the troop. If this is comomn among the Japanese macaques, the population dynamics of its regional population is more complicated than expected.
A systematic study was done with regard to the incidence of Candida albicans on Sesamum leaves at different stages of their development and during senescence. The pathogen was isolated consistently on the green leaves but its populations were minimal when the leaves underwent decomposition. Quantitative and statistical evidences were obtained to show that the pathogen multiplied profusely on the leaf surface, and especially so, at the onset of senescence when flowering of the plant was at its maximum. It is concluded that the phylloplane is one of the natural habitats for the occurrence of C. albicans.