Artificial apawning beds for halfbeaks made of palm hair and "shida-mabushi" were moored to light buoys at six places in the central part of the Seto Inland Sea during the spawning season of the fish in 1963. "Drifting experiments", in which the artificial spawning beds were moored to a drifting ship, were also carried out. More than 25,000 eggs were fastened respectively to two spawning beds moored to two light buoys in Bingonada for 9 days in late May. The number of eggs fastened to the artificial spawning beds, however, was generally small, compared with the spawning conditions of the fishes to drifting seaweeds in this region. Halfbeaks spawn well on those objects which spread horizontally near the sea surface, while they scarcely spawn on objects hung vertically. The spawning beds must be set in such an area where the tidal current is not so strong. Half beaks spawn eggs at night as well as in the daytime. The number of eggs spawned by one female at once is probably in the range between 600 and 800.
The intertidal zonation of the marine algae along the coast of Nie Bay, a small inlet in the Sea of Kumano, was studied. The field work was carried out in the winter of 1965. As the results of the investigations, two communities were found. The Hizikia fusiforme-Eisenia bicyclis association was found along the exposed shore of the bay, and the Monostroma nitidum-Scytosiphon lomentaria association along the sheltered shore. The important factors with regard to the distribution of the algal communities are the size of the bay and the wave action.
Der Zersetzungazustand der Laubstreuschicht (L-und F-, H-Horizont eingeschlossen) wurde unter drei Waldbestanden in einer Sukzessionsserie : Pinus-, Pinus-Cyclobalanopsis und Shiia-Klimaxwald, untersucht. Vier (25×25m)-Quadrate wurden in jedem Waldbestande eingerichtet, um die Probestreu zu entnehmen. Diese Flachengroβe ist durch eine Art-Areal-Kurve (Abb. 1) der abgefallenen Blatter als ausreichend festgestellt worden. Die abgefallenen Blatter sind feldmaBig von ihrem Abbauzustand als Ganzes geschatzt (Tabelle 3.1). Aus den gesammelten Proben wurden der spezifische Zersetzungsgrad (SZ) und der Bestandszersetzungsgrad (BZ) (Tabelle 4) ausgerechnet (Tabelle 3.2). Diese Werte wurden mit Dichte (D) und Gewicht pro ha (PR) analysiert. Σt (monatliche Summe der Mitteltemperatur uber 10℃) durch Σx (monatliche Summe des Sattigungsdefizits mm Hg) hat sich als geeigneter Zeigerwert fur die Zersetzungsleistung erwiesen. Der Laubfall findet im Shiia-Wald im Vorsommer statt. Das ist vielleicht eine okologische Eigenschaft von der Klasse Lauraceo-Fagaceetea semperviretns, die auch in der Gebirgsregion Formosas nach SUZUKIS Erfahrung gilt.
In the earliest stage of growth, almost all of the plants which have a resting period, begin their growth entirely depending on the reserve substance. The size of a newly formed plant body depends on both the amount of the utilized reserve substance and the economic ratio, or the efficiency of conversion of the reserve substance to the active plant body. The effect of the amount of the reserve substance on the economic ratio was examined with potato tubers of different sizes, and it was found that the ratio remained approximately constant (0.4-0.5) independently of tuber size. Almost the same ratio was obtained in the growth of the rice seedling in the dark under a wide range of temperature (15-30℃). So far as the present and other available data are concerned, it may be said that the plants, of which the reserve substance is mainly composed of carbohydrate, give more or less the same economic ratio of 0.5,irrespective of the difference in the initial amount of reserve substance and temperature.
Japanese investigators of soil animals assembled in Minoo, near Osaka, to compare their sampling and extracting techniques with each other. The samples were taken from the same forest stand and brought back to each investigator's laboratory to be treated by his own technique. The results of the discussion on the comparison of each technique are as follows : (1) Unit sampling area should be in concordance with the sizes of the animals. Thus the unit sample area of 25×25cm^2 and 5×5cm^2 was recommended for medium and small sized animals respectively. (2) Sampling depth is also recommended to be a multiple of 2.5cm. (3) Taking samples from a vertical section would prevent soil contamination. (4) Soil sampler as a container would facilitate protection of the samples from damage due to desiccation, pressure and so on during transportation. (5) Extraction should be conducted under rather weak heat and fairly long duration.
Niigata Prefecture is situated at about the middle of the coast of the Japan Sea. The coast-line of this prefecture is 298.0 kilometres long, being the longest in Japan. On the coast, which is considerably eroded by the northwestern waves in winter, are many sand dunes. The Hakusan Shrine at Noo in the southern part of this long coast-line, the Miyakawa Shrine at Kashiwazaki in the middle part, and the Yawata Shrine at Katsuki in the north. Each shrine has a relict stand of forest. As for the climate, most parts of this prefecture belong to the cool temperate region from the viewpoint of plant geography. The plant community of the climax forest at the Miyakawa Shrine was investigated. This forest area is classified into three stands, each dominated respectively by Neolitsea sericea and Zelkova serrata, Pinus Thunbergii and Quercus mongolica var. grosserata, and Cryptomeria japonica. The structure and composition were studied by the nest-quadrat method of 5×5m and 2×2m, the summed dominance ratio based on cover and frequency was described. The most important stand is the Neolitsea sericea community which is kept as a natural climax ; the other two stands are not so natural. It is very interesting ecologically that Neolitsea sericea, one of evergreen tree species in the warm-temperate region makes the climax forest, being in contact with the summer-green forest dominated by a deciduous tree, Quercus mongolica var. grosserata, in the cool-temperate region in Japan. This forest stand indicates a kind of ecotone of the coastal forest. The Neolitsea sericea forest belongs to Shiion Sieboldii and is equivalent to the Machilus Thunbergii-Polystichum aculeatum var. japonicum association widely distributed in the coastal area of the warm-temperate region of Japan.
In this paper, the vertical distribution of freshwater planarians in Hirosaki City, the Mt. Iwaki district (Lat. 40°30′N. to 40°50′N. and Long. 140°15′E. to 140°30′E.) and in the Juniko district (Lat. 40°32′N. to 40°35′N. and Long. 139°56′E. to 140°00′E.), all in the western part of Aomori Prefecture, Honshu, is reported. Mt. Iwaki (altitude, 1625 metres) is an extinct volcano of the Chokai Volcanic Zone and is situated at the south-western corner of the Tsugaru Plain. The Juniko district near the seashore of the Sea of Japan is characterized by many ponds or marshs. The main river systems in the area surveyed are the Iwaki and the Narusawa. The surveys were made in the summer of 1965 and in the spring and summer of 1966. In the area surveyed, five species of freshwater planarians, Dugesia japonica ICHIKAWA et KAWAKATSU, Phagocata vivida (IJIMA et KABURAKI), Phagocata teshirogii ICHIKAWA et KAWAKATSU, Polycelis auriculata IJIMA et KABURAKI and Bdellocephala brunnea IJIMA et KABURAKI, were found. D. japonica and Bd. brunnea were found to be common in many springs in Hirosaki City. Small populations of Ph. vivida and of Ph. teshirogii were also found in some of these springs. In the other districts of the area surveyed, D. japonica, Ph. vivida and Pol. auriculata were widely distributed. D. japonica was found in the stations below the altitude of about 525 metres (inhabitable water temperature range, 9.0〜25.0℃). Ph. vivida was found in the stations within the altitude range from about 40 to 620 metres (5.0〜15.0℃) above sea level. It is however clear that Ph. vivida is the species of nondominance in the western part of Aomori Prefecture. Pol. auriculata was common in the stations within the altitude range from about 200 to 1320 metres (5.0〜14.5℃). The type of the vertical distribution in the area surveyed is shown as J-JV-JVA-VA-A (J : D. japonica ; V : Ph. vivida ; A : Pol. auriculata). The geographical distribution and the breeding of Bd. brunnea were also discussed. According to the best of our knowledge, this species is distributed in Middle and North Honshu (from Kyoto City in the Kinki Region to the Shimokita Peninsula in the northernmost part of the Tohoku Region). In general, their active breeding season was from early February to mid-May. In one breeding period one worm laid one cocoon of 2 to 2.5mm in diametre. The hatching of the cocoons was observed within 23 to 37 days after the laying. In the laboratory cultures, 3 to 12 jveniles were released from one cocooon.