(1) Cyanine dyes of ten different structures were tested for their antibacterial activities against various kinds of bacteria. It was found that they act strongly bactericidally against Gram positive bacteria but less strongly against Gram negative bacteria with the exception of Aer. aerogenes, H. pertussis and V. cholerae. (2) Bactericidal activity of some of the cyanine dyes was found to be several hundred times as strong as that of mercurochrome or rivanol. (3) Some of the cyanine dyes have induced, by contact with bacteria at a sublethal concentration, a strong resistance of V. cholerae against them, while S.aureus and B. sublilis showed only slight capacity of developing resistance against the same substance. The strain of V. cholerae which had become resistant against a cyanine dye was found to be non-resistant to mercurochrome and streptomycin, but decidedly resistant to other cyanine dyes, styryl dyes, acriflavine, crystal violet and methylene blue. (4) Test with subcutaneous phagocytes of rabbit has revealed that the cytotoxicityof a cyanine dye was 100 times as strong as that of mercurochrome. (5) Some of the cyanine dyes were found to have no cidal activity upon the intestinal parasite of toad (Rhabditis).
(1) When ordinary strains of S. aureus or E, coli were cultured in the presence of penicillin or streptomycin, the growth curve showed a characteristic upswing at later stages of culture. This phenomenon was shown to be due to the development of resistant cells which either had existed sparsely in the original inocula or had spontaneously appeared as a mutant during the growth of less resistant cells. In contrast to the bacteria mentioned above, L. casei produces a population which is quite homogeneous in respect to the resistance of individual cells towards penicillin and streptomycin. In the culture of this bacterium, there occurred no upswing of growth curve in the presence of said antibiotics. (2) The rise of growth curve owing to the development of resistant cells was also observed when ordinary strain of S. aureus was cultured in the presence of furacin, a strain was obtained which may be regarded as practically “pure” or homogeneous in respect to the resistance towards the drug. With this strain no ascension of the growth curve occurred at later stages of culture in the presence of furacin. (3) The possibility of the occurrence of selective growth of spontaneous mutants under the influence of various antibacterial substances was discussed.
A critical review of the existing theories of endosperm morphology has been attempted. In accordance with a reconsideration of endosperm phylogeny, an evolutionary concept has been suggested to explain the various aspects of the development of endosperm. Evolutionary trends have been discussed on three main lines: 1. Increasing complexity in chromosomal constitution; 2. Gradual transposition in relation to fertilization; and 3. Dominance of mitotic inertia and demand for stimulation. Consideration of these guiding tendencies coupled with the existence in apomictic plants of an autonomous endosperm, has resulted in the formulation of the theory of the “pre-destined” nature of the endosperm. It is shown that the endosperm in angiosperms is a tissue sui generis which should not be classified in rigorous chromosomal categories. The role of physiologico-evolutionary modifications is shown to be reinforced by a purely physiological coincidence, the fusion of the second male nucleus with the proendospermatic cell.
1. Concerning the formation of starch in guard cells, the author studied the increase or decrease of starch under natural conditions, the effects of concentration of hydrogen ions, amylase, plant juice and inorganic compounds on the formation of starch, and the substratum for the formation of strach. 2. Over ten kinks of plants were used as materials. Gladiolus and Zea Mays were appropriate to the experiments in the summer season, Narcissus Tazetta and Zephyranthes candida in the winter season and Tradescantia reflexa in all seasons. These plants were very suitable, because they had strong power of synthesizing starch from glucose-1-phosphate. 3. Daily increase or decrease of starch in guard cells under natural conditions is not so remarkable as in tissue cells, though remarkable difference by species was observed. When put in dark room, the starch within tissue cells rapidly disappeared, but that within guard cells, in some plants at least, increased for the first two or four days, thenceforth began to decrease little by little, and finally disappeared. 4. Different from in tissue cells, the starch in guard cells was never formed from carbohydrates, but only from glucose-1-phosphate, its lower limit of concentration for the formation being 0.0005mol. 5. The strach-forming activity in guard cells was stronger in the existence of weak acids, and the action of phosphorylase was recognized between the pH of 4.1-7.3 coinciding with the pH value at which the reserve starch of radishes was formed.