The animal, Tylos granulatus MIERS, and inhabitant of the sea-shore sand-dune, shows conspicuous daily rhythmic activity. It inhabits beneath the sea-shore sand-dune in the daytime and is active only during the night under natural conditions. The present paper states the results of some experimental observations on the modification of rhythmic activity in accord with its growing stage. Experimental observations were made with animals which were kept in the laboratory during May to June, 1952. I. Modifications in the mode of rhythmic activity in accord with growing stage of animal are shown as follows : a. The rhythmic activity of the youngest stage (with 5mm body length) belongs to dependent type of activity through 24 hours periods (Fig. 2). b. The younger one (with 10-15mm body length) is active only in the night and did not show any activity in the daytime, so the rhythmic activity in 24 hours periods belongs to independent type of rhythmic activity. But, in the night, activity of the animal are influenced with some environmental factors, such as, airtemperature, relative humidity and etc., so the nocturnal activity of the animal belongs to dependent type of rhythmic activity through 10 hours in the night. c. When the animal grows up (with 20mm body length), it shows typical independent type of rhythmic activity in 24 hours periods (Fig. 2). II. In spite of growing stage, the animal is always active in the night, and the animal shows the most sever activity in the same time, these phenomena are characterized the daily rhythmic activity of this animal (Fig. 2). III. MORI ('50) stated that daily rhythmic activity of a certain specles established not only by the combinations of mutations and natural selections, but also by directed and gradually accumulated modifications, and in my opinion, the daily rhythmic activity of this animal seems to have established by also the same process, from the results are shown in Figs. 1,2. On the other hand, the diurnal rhythm of this animal, is essentially a metabolic cycle synchronized with the external periodicity of day and night through the influence of variations in illumination, temperature and other environmental factors, on the nervous and endocrine systems, as stated by KLEITMAN
No social unit of epiphyte communities is used by internationally mutual agreement. The writers claimed, however, it will not be appropriate to use either the phytocoenosial, synusial or serule unit for any epiphyte community which is a partial one in the phytocoenosis of forest. They set forth reasons why they should establish another new system of units of epiphyte communities in forests. Consequently, the writers wished to coin other new terms of units, such as "epies", "epilia" and "epido" which are founded on the concept of epiphyte communities being partial ones in a forest of phytocoenosis. The units of epiphyte communities they claimed ought to be used regardless the units of any synusia in forests and without restriction of such units of phytocoenosis as sociation, consociation, association and alliance.
The northeastern mountains of Formosa are covered with natural forests. Here the writer reports the results of his survey of the district near Mt. Rara. Machilion Kusanoi is an alliance occurring along the valley. This is a subtropical rain-forest in the narrower sense (sunsu Rubel). Shiion stipitatse develops over the mountain-sides between the altitudes of 400m and 1400m. Above 1200 to 1300m, there are found the evergreen broad-leaved alliance of Cyclobalanopsidion paucidentatae, the coniferous one of Chamaecyparidion taiwanensis, and the deciduons forest of Fagion Hayatae. Shiion stipitatae and Cyclobalanopsidion paucidentatae are laurisilvae in Rubel's sense. But whether Chamaecyparidion taivaensis is an example of laurisilvae or not, is unider question. The annual range of temperature in this district is much smaller when compared with that in the northern limits of laursilvae in Japan. The vertical boundary between Fagion and Cyclobalanopsidion at Rarasan agrees with the annual mean temperature of 13℃. The numbers of ephiphytic species increase, as one ascends or descends from the area of Shiion stipitatae into that of Machilion or that of Cyclobalanopsidion or Chamaecyparidion. But the coverage values both of epiphytes and lianas decrease in the alliance found at the higher altitude, while hemicryptophytes increase both in number and quantity. Shiion stipitatae is a typical mixed forest, and those forests found either above or below this alliance are characterised with the tendency of single dominance when compared with Shiion stipitatae. This district can be divided into two parts. The northern half is under the direct infiuence. of winter monsoon, and has Cyclobalanopsidion and Fagion in the misty belt, while the southern half is shaded by the ridge of Mt. Mokko and the misty belt here is occupied with Chamaecyparidion instead of the broad-leaved forests.
Cosmopolitanism is one of the well-known features of the fresh-water plankton in general. Some copepods such as Calanoida of inland waters, however, have more or less its own restricted geographical distribution. This phenomenon in these copepods may be explained from the fact that the adaptation or migration of these forms from sea to inland waters has taken place in an age comparatively recent. From this point of view, our attention may be drawn to the brackishwater copepods, because they may be regarded as the important links connecting those in the freshwaters with their fellows in the sea. In Eastern Asia, two series of such copepods are observed, one in the Yangtae-kiang Valley, Central China, and the other in the territories surrounding the Sea of Japan. These two series show an obvious parallelism, consisting of closely related species respectively. In this case, the Sea of Japan, in the early stage of its formation, seems to have played the same role as the estuary of the Yangtse-kiang in Central China.
There are two controversal opinions concerning the nature of population growth of animals. GAUSE (1934), UCHIDA (1949) and others maintain that, under closed condition, the environmental resistance due to high density of population is the cause of the logistic nature of population growth, while VoOTE (1937,1938), MORISHITA (1950) and ITO (1952) claim that the emigration of a part of population is a very important factor for the regulation of overpopulation under open condition. The writer traced the growth of the population of Green Peach Aphid, Myzus persicae SULZER, on cabbage seedlings both under open and closed conditions. Under former condition, 20 or 40 parent aphids were liberated to a cabbage seedling with 8 to 10 leaves in a pot. The pot was pasted with tanglefoot on the margin, placed in a water tray and covered with gauze net to interrupt both the emigration and the immigration of the aphid. Under latter condition, five seedlings of the same growth stage were planted in a wooden frame bed and 20 parent aphids were liberated on the central seedling. The bed was covered with gauze net too. The results of observations can be summarized as follows : 1. Saturation density of the aphid was found lower under open condition than under closed condition, probably due to the occurrence of emigration under former condition (Table 2 and Fig. 2). There is a linear relation between the number of emigrants on logarithmic scale and the density of population, which is represented by the formula Y&0.68+0.27χ in Fig. 3A and Y=0.74+0.28χ in Fig. 3B. Therefore, the emigration plays an important role to regulate the overcrowding of the population (Fig. 4). 2. Intensity of struggle for existence as calculated after GAUSE's formula was found higher under the open condition than under the closed condition in spite of the lower saturation density under the former condition than under the closed condition in spite of the lower saturation density under the former condition. This is due to that the index of struggle for existence by this formula includes the regulating power of the emigration under open condition.
5 peat samples at Shimotashiro, Nakatashiro and Mt. Shibutsu (1810m) of the Oze district were studied palynologically. Pollen profiles of the first two stations show that a broad leaved forest tends to decrease in the upper layers, while conifers increase upward. This fact suggests that the upper layers correspond to Period R III and the lower to Period R II based on the zonation of Kamitashiro. That of Mt. Shibutsu shows a conifer stage throughout, corresponding to the upper layers of the above-mentioned profiles. The ash layers, in the pollen columns of Fig. 3,which we consider to be volcanic ash falls, were correlated to each other on the basis of pollen sequence.
About 160〜180 Japanese monkeys (Macaca fuscata fuscata) inhabit as a single group in Takasaki Yama facing the Beppu Bay in Kyusyo. As a problem of their social life, we investigated their nomadism in three times between May, 1950 and May, 1951,The conclusions from our observations are as follows : - (1) The monkeys lead the nomadic life taking their foods during the daytime in their course from one place to another. Ordinarily they are inactive at night. (2) The patterns of nomadism, which concern the range of movement, base, sleeping place, feeding place, path way and its distance per day, speed of locomotion etc., differ in seasons, because different seasons have their own kinds, distribution, productivity, and growth rate of plants which form the staple food of monkeys. (3) A pattern of nomadism remains stable so long as the production of any staple food is maintained. (4) In the shifting period from one stable season to another, the nomadic type becomes irregular and sometimes takes a mixed type of two seasons. (5) When ther food becomes poor in their territorial range, monkeys invade and make damages to the farm at the foot of the mountain. (6) The presence of a predominant male was proved by our observations, who leads and organizes the group in good order. But, to understand the dynamics of nomadism, we can not overlook the cooperative behaviors including their vocal communication and other integrative behaviors between the leader and other members.
I have studied on the variation of colony of a limpet, Acmaea dorsuosa GOULD, at Hadakajimaisland, near Asamushi Marine Biological Station and obtained the results as is shown in the following lines. 1. Position of colony of Acmaea dorsuosa GOULD is about decided in every year, but some of the colonies are newly formed in every year. Comparing the nature of colony formation in 1932 to that of in 1953,number of colonies are increased 2 times in these 20 years, but total number of individuals is increased only 0.72%. (see Table 1) 2. Comparing the vertical position of colonies of the limpet in 1932 to that of in 1953,positions of colonies in 1953 are about 25cm higher than that of in 1932 in the western part of Hadaka-jima-island, but it is about 7 to 12cm lower in 1953 than that of in 1932 in the eastern part of the island, and it is about 4cm lower or about the same in 1953 than that of in 1932 in the northern part of the island. 3. Comparing the direction and velocity of wind in 1935 to that of in 1953,SW, W and NW wind blow exactly stronger than other wind in 1935 (see Table 2) and W wind in 1953 blow stronger than W wind in 1935,but SW and NW wind are much decreased in 1953. Therefore, physiological tide level is diflerent each other. Namely physiological tide level in 1953 is higher than that of in 1935 in the western part of the island, but on the contrary, physiological tide level in 1953 is lower than that of in 1935 in the eastern part of the island. 4. Zonation of animals in the neighbourhood of the colony of the limpet in 1953 is compared with that of in 1935. Number of Mytilus crassitesta LISCHKB is distinctly increased in 1953 compared with that of in 1935,but number of Septifer virgatus (WIEGMAMM) is distinctly decreased in 1953 compared with that of in 1935. 5. Variaton of vertical position of the colony of the limpet seems due to variation of direction and velocity of wind, and not due to variation of inhabitants.