The effects of alcohols on the pollen tube growth, the germination percentage and the plasma streaming in the hair of the stamen of Tradescantia reflexa Rafin. were observed. Alcohols tested were as follows: Methyl, ethyl, n-butyl, sec-butyl, tert-butyl, iso-butyl, amyl, iso-amyl, n-propyl, iso-propyl alcohols and cyclohexanol. Various promoting and inhibitory effects were obtained, as shown in tables and figures. Especially, methanol and ethanol of 0.05% were effective as activators in many cases.
Electron-microscopic observations were made on M. glutamicus. 1. Polar granules which appear at some stages of incubation are thought to be volutin or metachromatic granules. 2. Very small volutin granules were also observed in the cells which were cultured in glucose bouillon. Size of these granules were 100mμ-150mμ in diameter. 3. Size of volutin granules increased to 300mμ-400mμ in diameter after 1.5h 7h culture in the synthetic medium. 4. The thickness of the cell wall is less than 10mμ and its density is lower than that of cytoplasm. 5. There are a few large vacuoles in cytoplasm. 6. Low density part which was slightly fibrous was observed in cytoplasm, and may be considered to be the nuclear site. 7. Usually, there are one to two vacuoles which contain a volutin granule of high electron density. 8. Volutin granule is consisted of many small vesicles whose diameters are 5 mμ-20mμ.
Subalpine coniferous forests mainly dominated by Abies mariesii and A. veitchii develop widely in the northern and middle Honshu. In Shikoku, however, the subalpine region is limited, and the climax forest occurs on a rather small scale. The mountains where the subalpine coniferous forest is found in Shikoku are Mt. Tsurugi, Mt. Sasagamine and Mt. Ishidzuchi, and the climax forest of the subalpine region is characterized by the dominance of Abies sikokiana (A. veitchii var. sikokiana). The floristic composition and the structure of this Abies sikokiana forest are presented in Table 1. Abies sikokiana dominates in the tree layer usually attaining to 6-10m. in height. Betula ermani, Pinus pentaphylla var. himekomatsu, and Sorbuscommixta occur frequently but are not always abundant. The shrub layer is constituted by Sasa spp., Menziesia pentandra, and others, but Sasa spp. are mostly dominant. The major species in the herb layer are Oxalis acetosella, Dryopteris austriaca, Cacalia adenostyloides, Majanthemum dilatatum var. nipponicum, and Oplopanaxhorridus var. japonicus. The forest-floor, where Sasa spp. are absent or are not abundant, is predominated by mosses such as Hylocomium splendens, Pleuroziumschreberi, etc. The floristic composition mentioned above has distinct resemblances to that of the Abies veitchii forest occurring in the Pacific side of Honshu. Though the forests of Abies veitchii and A. sikokiana may be included in one and the same association, a provisional name, the Abietum sikokianae, is given here. Abies sikokiana often comes down to an elevation of about 1500m. above sea-level. But the climax subalpine coniferous forest is of course not found in such an altitude, and Fagus crenata is still predominating. It is assumed that the area of the Abies sikokiana climax forest is at least higher than 1700m. altitude. The lower limit of this forest usually comes in contact with the Abies homolepis forest or the Fagus crenata forest, and the Tsuga diversifolia forest is seldom found in the lower part of the subalpine region of Shikoku.