Entropy of the existence of the species on the plant community is calculated from the data of 30 concrete communities on Noto Peninsula, Ishikawa Prefecture, Japan. Entropy and functions of entropy are the interesting expression of fidelity of the plant community.
The size distribution, regression of the female body length on egg numbers in a brood, the body weight-length relation and the population density of Ligidium japonica were investigated at the warm temperate evergreen broad leaf forest of Mt. Kiyosumi, Boso Peninsula, Japan. From these measurements and from the rate of respiration and the calorific content of the animal, the amounts of production and respiration of the population were estimated. The amount og reproduction in dry weight for the population was estimated at 273.8 mg/m^2/year, or 1.40 kcal by using the calorific value 5.1 gcal/mg dry weight. The growth of them was estimated at 3285 mg fresh weight/m^2/year, or 2.13 kcal. The production for the population amounted to 3.5 kcal/m^2/year. The annual oxygen consumption of the animals was estimated at 3268 O_2 cc, c^2. Using the coeffccient 4.9 gcal/O_2 cc, the respiratory energy loss for the population was estimated at 16.0 kcal/m^2/year. The annual metabolism for the Ligidium population therefore amounted to 19.5 kcal/m^2 from September 1962 to August 1963. It was estimated that about 80 per cent of energy assimilated Ly the Ligidium japonica population was consumed for their respiration.
The microorganisms of rumen exist in a remarkable symbiosis with the host animal : the rumen provides a suitable environment for the continuous culture of the micoobial population, and the microorganisms produce the nutrient substances essential for the host animal. It is known that the main functions of the rumen microorganisms are to produce the Volatile Fatty Acids (VFA), such as acetate, propionate, butyrate, from the foodstuffs ingested.IIn this paper, some effects of the sdditions of various substrates upon the production of VFA were studied, with special reference to the change of the protozoal population. The apparatus employed in the present experiment inolves the use of the cellophan sac (made in Visking Co. Ltd., ) containing the rumen fiuid obtained from the sheeps fed on hay plus concentrates, which was strained through two layers of cheese cloth immediately after removal. The rumen fluid in the cellophan sac, which is suspended in a water-bath containing the mineral salt solution (Table 1) similar in composition to the rumen fluid and adjusted to pH 6.8,is gassed with CO_2 and the run is conducted at 39℃ for six hours (Fig. 1). Such apparatus could sustain a in vivo microflora, because the sac is simulated in the part which diffusion plays in the activity of the in vivo rumen. This paper records the changes of pH value, the concentration of VFA and the cell density of the protozoa when such substrates as Hydrocellulose, Cellulose powder (powder of filter paper). Starch and Casein are added to the cellophan sac containing the rumen fluid to make the final concentration of 4 per cent. For analysis of the VFA, the column chromatographic method was used. The pH was determined with a glass electrode. The cell number of the Protozoa was counted under the microscope using a mess-slide glass. As the control, the VFA, pH and the cell density of the Protozoa were also estimated on the rumen fluid without any substrate. Table 2 shows that the concentration of total VFA increased following the addition of Hydrocellulose, Cellulose powder, Starch and Casein. Especially, the addition of Starch and Casein accompanied a greater production of the VFA than in the case of adding Hydrocellulose and Cellulose-powder. However, when the data of each component of VFA were converted into percentage of the total acids titrated, similar pictures were given (Fig. 2). It is noticeable that, although different substrates yield different amounts of total VFA, the production-pattern of Vhe components of VFA, acetic acid, propionic acid, butyric acid and the other acids, were nearly the same. The cause of the result remains obscure. The pH maintained nearly a neutral value or slight acidity on adding substrates except Starch, the addition of thich reduced the pH later six hours(Fig. 3). The possibility of a pH effect in vivo was noted earlier by several workers, who observed that the cell density of the Protozoa appeared to be low when the pH value was low and acid concentration was high. In this experiment, the cell density of each Protozoa in six hours after adding Starch were considerably similar to that of the begining, suggesting no damage to the Protozoa due to the decrease in pH and the production of a greater amount of VFA. Similar trends can be noted on adding the substrates except Starch (Fig. 4). Accordingly, it seems that the decrease of protozoal density after feeding in vivo (Fig. 5) depends much more on the dilution with food, water and saliva than on the inhibition of cell division by lowered pH caused by the acid production in the rumen. Besides, the result that the total VFA are significantly low on adding Hydrocellulose and Cellulose powder is likely to be due to the ingestion of Cellulose by Protozoa as well as the slowly fermented nature of Cellulose, because there were seen a fairly large number of Polyplastron swallowing large amounts of Cellulose powder and Hydrocellulose which are seen tightly packed and remain in their
The changes of water level in the Sarutani reservoir are caused by the amount of rainfall, water-drainage to the water power, irrigation and control of the flood. No aquatic plants and no limno-gastropoda are found in this lake, due directly or indirectly to the high frequency and great degrees of the annual change of the water level. The lake shores are so steep that it is difficult for the sediments and organisms to deposit or to stay on the bottom of the shore zone. Such a zone may be unfavourable to the habitats for almost all species of aquatic plants and limno-gastropoda. The standing-crops of Zacco platips and Zacco temminkii are ample in this lake ; this depends on the following two facts : 1) the spawning period of the fishes agrees with the period of comparatively slight change of water level in this lake, and 2) the egg period of the fishes is short. Hypomesus olidus is not so abundant in this lake, in spite of that the young fishes of this species have been stocked annually. It can be said that the natural increase of this fish is controlled by the next two reasons, i.e. 1) its spawning time falls in the period of low water level in winter in this lake, and 2) the egg period is long.
The intertidal zonation of the marine algae along the coast of Shimoda Bay, a small inlet on the Pacific shore of the Izu Peninsula, was studied. The field work which forms the basis of this paper was carried out in the spring of 1964. The results of the investigations have made it clear that the Hizikia fusiforme-Eisenia bicyclis association is distributed along the whole coast of Shimoda Bay. It consists of three belts, from above downwards, Myelophycus caespitosus, Hizikia fusiforme and of Eisenia bicyclis belts. It seems that the joint work of the shape of the small bay, the influential Black Current and the surfs from the open-sea have resulted in the production of the vegetation of marine algae. The association is a typical one of the open-sea communities along the coasts of the Pacific Ocean, and it is also a unique algal community of Japan, of the Far East. The Gigartina intermedia-Sargassum sagamianum association which is distributed in Sagami Bay and Suruga Bay is not found in this bay, and the Monostroma itidum-Scytosiphon lomentaria association which is one of the inland-sea communities was also not found in this bay.
Evetria cristata WALSHINGHAM and Dioryctria splendidella H.-S. are well known shoot moths attacking pine trees. The former causes damage to the shoot and cone, but the latter further to the stem. The present auther has carried out experiments on the following items to ascertain the density effect acting in natural populations of both species : the larval mortality in two different population densities, one larva and five larvae per a small pine seedling ; the influence of the injury by the shoot moth on the cone growth ; and the mortality of the hibernating generation in the cones in which some of them have been attacked by the larvae of the previous hibernating generation. One (low density) or five (high density) individuals of the first instar larvae of D. splendidella were laid in the shelter of the bud scales of the top shoot of each small pine seedling, Pinus thunbergii or P. densiflora. The dispersal of the young larvae was limited only to the top shoot area during 20 days after they were laid, their mortality was, however, higher in the low density than in the high density. There is no difference between the survivour-ship (l_x) curves in the low and high densities after the 11th day. Cone damaged by the previous hibernating generation of E. cristata and D. splendidella does not appear to be a favourable site for the oviposition of E. cristata adult of the generation. But, it seems to be superior for the larval growth. Because the mortality of the population living in the undamaged cone is significantly higher than that in the damaged cone at 5 per cent level.
In the present paper, the vertical distribution of freshwater planarians in the Mt. Wenshiri district, the Kitami Mountains in North Hokkaido, is reported. The highest peak, Mt. Wenshiri, is 1142 metres above sea level (Lat. 44°13′N. and Long. 142°53′E.). The main river systems of the area surveyed are the Okunayoro, the Okoppe, the Mookoppe and the Shokotsu. The Okunayoro River, the upper part of the Teshio River, discharges into the Sea of Japan ; the other three rivers empty into the Okhotsk Sea (fig. 1). The surveys were made in August 1962 and August 1963. In the district, the four species of freshwater planarians, Polycelis sapporo (IJIMA et KABURAKI), Polycelis akkeshi ICHIKAWA et KAWAKATSU, Polycelis schmidti (ZABUSOV) and Dendrocoelopsis lacteus ICHIKAWA et OKUGAWA, were found. Pol. sapporo, the commonest numerous-eyed white flatworm in Hokkaido in North Japan, was distributed in the localities below the altitude of about 420 metres. It was common in rivers, creeks, brooks and brooklets. Pol. schmidti was, however, common in the cold-water streams and springs within the altitude range from 300 to 560 metres. The animal is the common dark colored Polycelis species in North Hokkaido and is the most stenothermic among the Japanese freshwater planarians (cf. Kawakatsu 1964,1965). Pol. akkeshi, another numerous-eyed white flatworm in Hokkaido, was collected in some localities near Oshorokko (Okoppe River System). Den. lacteus was only found in two localities at Nishiokoppe and Kamiokoppe (alt. 100〜140 m). The inhabitable water temperature range of the above-mentioned four species found in the Mt. Wenshiri district is as follows ; Pol. sapporo (8.0〜16.0℃ ; including the data of Pol. akkeshi) ; Pol. schmidti (7.0〜14.0℃) ; Den. lacteus (7.6〜11.7℃). Pol. sapporo and Pol. schmidti were found together where their inhabitable water temperature overlapped. The habitats of planarians are also described in detail. No planarian was found in any localities of the Sakuru Waste Land, an argillaceous zone along the upper part of the Shokotsu River (fig. 1,table 1). The type of vertical distribution of the district is S-SC-C (S : Pol. sapporo ; C : Pol. schmidti). The result of the present investigation shows that the planarian fauna and the type of vertical distribution in the Kitami Mountains differ from that of the Mt. Daisetsu district in Middle Hokkaido(cf. YAMADA 1962 ; YAMADA & TANJI 1962,1964).