Many species of “Sasa” (bamboo grasses) are distributed endemically in Japan. They often constitute the characteristic grassland communities or the shrub strata of open forests in montane and subalpine zones (or cool temperate or subarctic zones). This study was carried out on closed communities of different dominant Sasa species at four stations of the central Honshu and of Hokkaido. 1. Descriptions as to temperatures, precipitations and soil conditions were given as the basis of further discussion of Sasa communities. 2. The characteristics of the communities were investigated by the stratifying clip method in the weight of leaves, culms, subterranean parts and of entire plants, the height of community, the number of culms, the productive structure, the leaf area index, etc. 3. Among the communities with different dominant species and different localities, marked differences were realized in standing crop, height of community, longevity of culms, and number of culms. The standing crop increased with longevity of culms and height of community, and it is similar to or larger than the standing crop of other herb communities. 4. The amount and vertical distribution pattern of leaves of these Sasa communities were more or less the same. The leaf area index was 4.5-5.4, the extinction coefficient of light in the community, 0.7-0.9, and the light transmissibility of a leaf was about 10%. 5. On the ground surface of these Sasa communities, there prevailed extremely low light intensities with small deviation, enough to be fatal against seedlings of many species.
Nitella inokasiraensis, die zu den Monoarthrodactylae gehört, wurde entwicklungsgeschichtlich untersucht. Der Hauptsproß besitzt ein unbegrenztes Spitzenwachstum. Der Vegetationspunkt ist eine halbkugelförmige Scheitelzelle, die unterwärts eine Gliederzelle trennt. Die Gliederzelle teilt sich in eine Knoten- und Internodialzelle, die sich danach ohne Zellteilung streckt. Die Knotenzelle teilt sich zuerst in zwei nebeneinanderliegende Halbierungszellen, dann erfährt sie eine Reihe von gesetzmäßigen Teilungen, aus der die sechs peripherischen Zellen und die zwei Zentralzellen entstehen. Jede von den peripherischen Zellen wölbt sich zuerst nach oben schräg, dann teilt sie sich in eine Basalzelle und eine Blattanlage. Aus den Basalzellen des ersten und zweiten Blattes kommen die zwei Seitensprosse und die zwei Seitenblättchen vor. Bei Nitella inokasiraensis erfährt die Basalzelle keine Knoten-Internodium-Teilung. Nitella inokasiraensis ist diözisch, sie entwickelt ihre Antheridien oder Oogonien auf den Blattknoten. Die Eimutterzelle schneidet die drei Wendezellen außer der Eizelle ab. Es ist mir eine angenehme Pflicht, an dieser Stelle Herrn Prof. Dr. H. Ono und Herrn Prof. H. Kasaki für ihre Anregungen und stetige Leitung meinen besten Dank auszusprechen.
Two new species of Spirillum have been isolated from the putrid media in which the putrid bodies of two species of the fresh water shell fishes, Corbiculajaponica Prime and Cipangopaludina malleata (Reeve) laid. On the basis of the morphological, cultural and physiological characteristics, the spirillum isolated from Corbicula japonica Prime is diagnosed as a new species, and it is named Spirillummetamorphum from its metamorphosis; and also the spirillum isolated from Cipangopaludinamalleata (Reeve) is diagnosed as a new species and named Spirillum crassum because it has a stout cell.
As a first step to study the primary production in the mountain section of the River Arakawa, the standing crop of the sessile algal community was measured by means of the chlorophyll method. From the ecological point of view, the mountain section was divided into two parts; the canyon section and the lower section. 1. The annual mean value of chlorophyll content on the river bed was 25mg./m.2 in the canyon section and 70mg./m.2 in the lower section. These values coincide fairly well with those measured in the ordinary eutrophic lakes in Japan. 2. Throughout the watercourse, definite rhythm was observed in the seasonal changes of chlorophyll content on the river bed. The peaks were found in winter in the canyon section, while those in lower section were in fall. 3. There is a linear correlation between the chlorophyll content and cell number in the sessile algal community of the mountain river. 4. The main factors determining the standing crop of the sessile algal community in the mountain section of the River Arakawa can be summarized as follows; (1) unstable aquatic environment of river bed caused by the hydroelectric impoundment, (2) physical action such as scraping and burying referred to the flood of river by heavy rain, and (3) the precipitation of the coarse bed load originated from the construction of the impoundment and of the fine lime stone outflowed from a settling pool of Titibu Mining Industry.
1) The spring wheat, Konosu No. 25, was cultured aseptically in test tube containing the modified White's medium under various light conditions. 2) The flowering and growth of spring wheat were depressed under the prolonged short days, and especially in darkness. 3) The photoperiods inserted in continuous darkness promoted flowering and growth. The photoperiod of 5 days was not enough for flowering, but that of 10 days was sufficient. 4) The early growth stage from the sixth to the tenth day after germination was most sensitive in photoperiodic response. The sensitivity decreased gradually with proceeding growth stages in dark culture. 5) The plants cultured in darkness for 50 days did not initiate flower primordia, but those cultured for 160 days initiated on the tillers and rarely on the main axes.
Changes in gibberellins occurring during seed development and germination of Pharbitis Nil were studied by means of paper-chromatography and rice seedling method. The amount of gibberellin reached its peak on the 13th day after anthesis and thereafter markedly decreased. The maximum amount of extracted gibberellin corresponded to 0.35μg. of gibberellin A3 per seed. Gibberellin extracted from etiolated seedlings decreased gradually after germination in the dark. Three zones of gibberellin activity were found at Rf 0.0-0.2, Rf 0.3-0.5, and Rf 0.55-0.7 on the chromatograms developed with the mixture of iso-propanol/ammonia/ water (10:1:1). The activity of Rf 0.55-0.7 was attributed to the chemically known gibberellin A1, A2, A3, or A4. In initial stages of seed development the gibberellin activity appeared mainly at Rf 0.55-0.7, while in mature seeds and seedlings at smaller Rf values of 0.0-0.2 and 0.3-0.5.
The vertical distributions of the zoospores of aquatic fungi were studied in some Japanese lakes. The distribution of the zoospores in lake waters varied with seasons. There were two main types, i.e, homogeneous distribution and stratum one. The former appeared mainly during the circulation period and the latter was observed during the stagnation period. All species of aquatic fungi were distributed only in the epilimnion during the stagnation period, while some differences in the vertical distribution of the fungi were observed during the circulation period. The zoospores of Saprolegnia were distributed only in the surface layer, while those of Achlya and Aphanomyces were seen mostly in the bottom water. The zoospores of Pythium were distributed homogeneously from the surface to the bottom layers.
Some of the dikaryons obtained by pairing of monosporous mycelia from the wild fruit-body “h” of Coprinus macrorhizus form, microsporus (a tetrapolar fungus) produced undeveloped rudiments of fruit-bodies or abnormal fruit-bodies with usual stipes and closed or half- open pilei. This abnormality of fruit-body formation is a hereditable character, being controlled by a single recessive factor, f. No linkage exists between the factor f and the incompatibility-factors, A and B.