1. The adaptability of mosses to their different habitats was ascertained by researching into their minimum hydrability within which mosses are able to survive, and by making inquiries the relationship between it and water economy in mosses. 2. On the relationship among maximum hydration (M), hydrability of air-dried samples (A), minimum hydrability (m) and the hydrability of “dead-and-air-dried” samples (a) of xerophilous (X), of merophilous (Me) and of hygrophilous (H) mosses, the following formulations seem to be given: M, X<M, Me<M, H; m, X_??_m, Me<m, H; A, X_??_m, X_??_a, X; A, Me_??_m, Me>a, Me; and A, H(dead)<m, H. 3. It seems that xerophilous mosses do not easily reduce their water below the quantity of their own minimum hydrability when they are air-dried, that they are capable of imbibing vapour in the air which is not saturated with vapour bait is low in relative humidity, and that they are capable of maintaining water above their own minimum hydrability in the air. But it seems that hygrophilous ones have not such peculiarities. These are probably caused mainly by the peculiarities of their protoplast. 4. It seems that maximum hydration and minimun hydrability being low in xerophilous mosses is favourable for their activities even in relatively dry conditions; on the other hand, it seems that hygrophilous ones, whose both the hydration and hydrability are high, are capable of being active only in the condition of environments having fairly much water in them. 5. “Dead-and-air-dried” samples of xerophilous mosses have the water-holding nature being nearly equal to that of air-dried (living) ones; this behavior seems to be important especially in their ecology.
1. During the microbiological investigation of the Oze-Moor which is situated in the northern part of Nikko National Park, the writers found the socalled “Red and Green Snow” on the snow left unmelted of several locality about 1500-1800 meters above sea-level in May-June 1951. They were also given the samples of red snow which were collected on the mountain ridge (ca. 2000m.) of Mt. Shirouma in May 1951 and on the snow valley (ca. 2500m.) near Mt. Eboshi in August 1951. These were spreading over the snow surface as small irregular patches measuring from several centimeters to one meter in diameter. 2. Cryophilous species determined from these samples are as follows. Fungi: Chionaster nivalis, Selenotila nivalis. Algae: Chlamidomonas nivalis, Chodatellabrevispina, Scotiella nivalis, Raphidonema nivale, Raphidonema Tatrae. Japanese Chodatella brevispina seems to be the slight modification of the European type differring in its having thicker and longer spines (2.1-2.8μ long). As for the non-cryophilous fungal members, the yeast-like cells, Chytridiaceous zoosporangium, hyphae of Dematium, spores of Guepiniopsis, Prosthemium, Scolecosporium, Asterosporium and others may be mentioned, Furthermore, Mucor hiemalis (-), Penicillium sp., several species of bacteria were separated as pure culture. 3. The main element of red snow is Chlamydomonas nivalis which was found in the stage of chlamydospores, some of them having gelatinous outer membrane. 4. The main element of green snow is commonly Chodatella or rarely Chlamydomonas. This type of green snow seems to be different from European Raphidonema- Type and American Chlamydomonas-Type. 5. Ph-range of green snow was 4.2-4.8 in half melting condition of materials. 6. Red snow was found in such a place exposed to the direct rays of the sun as mountain ridge, snow valley or Fagus-forest. On the contrary, green snow was spreading in the dark places of coniferous forest. 7. Chionaster nivalis is a kind of fungi and seems to pass the summer season in the stage of chlamydospores which are supposed to be formed by the conjugation of two cells. 8. We are now studying the life history of Chlamydomonas nivalis, Chionasternivalis and Selenotila nivalis, the latter two being not yet settled in their systematic position. The question how they live in summer season is left unsolved.