1. By means of the agar plate method, the action of 2-hydrazino-tropone and 7-bromo-2-hydrazino-tropone on mitotic cells was investigated in the Tradescantia test in vivo. 2. In a certain range of concentrations of these tropone compounds, swelling of the nucleus, of the cytoplasm and of the chromosomes occurs. In this state, not only the swollen prophase nuclei can continue the mitotic processes but also mitosis occurs de novo; most of the mitotic cells, however, become binucleate cells by the disorganization of the phragmoplast in the telophase. 3. These tropone compounds scarcely act on the atractoplasm, but due to the stickiness of the swollen chromosomes sometimes introduce bridges merely in appearance in the telophase. 4. From the standpoint of the cell biology, the relationships between the swelling of the prophase nuclei and the disorganization of the phragmoplast and the susceptibility of the prophase nuclei are discussed.
The effects of various metabolic poisons and reduced oxygen tensions on the motive force of protoplasmic streaming in the plasmodium, Physarum polycephalum, were investigated by means of Kamiya's dynamoplasmometry. Following results has been obtained. 1. No considerable changes in the motive force responsible for flow observed by removal of oxygen. Soon after the plasmodium was placed in fresh air, however, the motive force was slightly depressed for a while prior to its recovery. 2. Similar results were also obtained in the case of CO-treatment. It was shown on the motive force-time curve (dynamoplasmogram) that the plasmodium shows negative taxis to CO. 3. Pure O2 administered to both compartments of the chamber, inhibits the generation of the motive force to a certain extent. 4. By the application of the relatively high concentrations of HCN, the magnitude of the motive force is increased considerably at first, but is soon followed by a decrease. Then, the protoplasm ceases to flow without coagulation. 5. Plasmodium gains a tolerance for HCN in the case of the re-peated application of it. 6. In 10-4M. NaN3, the motive force decreases slightly, but satisfactory recovery was obtained in this case. 7. Other non volatile poisons were also investigated.
1. There is no recognizable difference between ordinary samples of PNA and a sample of highly “polymerized” PNA (molecular weight: cir. 800, 000) with respect to the preferential combination with pyronin when subjected to the reaction with methyl green-pyronin. In this connection it is of importance to examine the staining properties of nucleic acids always with the mixture of methyl green and pyronin, not with either methyl green or pyronin alone, because every type of nucleic acids is potentially stainable with both methyl green and pyronin, when each of these dyes is allowed to react separately with nucleic acids. 2. Several additional observations on the metachromasia of thionin caused by nucleic acids in vitro and in situ and on the electrostatic nature of the staining of tissue nucleic acids are reported.
1. The impedance of the plasmodium of a slime mold Physarum polycephalum was measured by using an alternating current Wheatstone bridge. A substitution method was used, and the frequencies applied were 30, 100, 300, 1000, 3000, and 10000 cycles per second. 2. The impedance at a certain frequency changed rhythmically with a period which was found to be equal to that of the rhythmical change of protoplasmic streaming. 3. The “frequency impedance loci” obtained were essentially the same as those of other living systems reported by Cole, Curtis, and others. The frequency at the maximum reactance was 100-1000 cycles per second and the phase angle was 48±3°. 4. The impedance had a polarization impedance, consisting of series resistance and a series capacitative reactance as its components, both of which were power functions of frequency. This work was aided by the Scientific Research Expenditure of the Ministry of Education. The author is indebted to Messrs. Fujita, Shimamura, and Ikeda of the Electrotechnical Laboratory for their kind help and criticism throughout the course of this work. Thanks are also due to Prof. H. Tamiya for his interest and advice in the preparation of this paper.
1. Due to the effect of K-ions the matrixes of chromosome swell and the chromonemata uncoil. Accordingly by the use of K-ion solution in adequate duration and concentration the matrixes swell or are destroyed and make the chromonemata observable. 2. For this reason, 0.1% aqueous solution of KOH or 1% aqueous solution of KCNS makes the chromonemata clear when the chromosome is pretreated with this solution for two minutes. The expenses of this work were partly defrayed by a grant from the Science Research Fund of the Ministry of Education.
1. The TCs and PMCs taken out from the anther of Tradescantia, Allium, and Canna into different kinds of mol/l sucrose solution and into liquid paraffin were studied. 2. The osmotic pressure of the vacuoles in the cytoplasm of the TCs of Tradescantia as well as of Allium is very high, so that when enough water is given to the TCs, they absorb it and swell until the structure in the cell loses its identity. 3. TCs surrounding the PMCs in the IM prophase are soft and elastic or rather fluidic, so that they spread around the PMCs even when the PMCs are separated from each other. The TCN at least in Allium, however, keeps its structure, probably the metabolic action too, throughout the meiotic stages until the pollen grains develop in the anther. 4. In the TCs of Tradescantia there appears a large quantity of raphides which show that a special physiological action is taking place in them. 5. The osmotic pressure of the TCN increases during the meiotic stages of the PMC proceeding from the premeiotic stage to the end of meiosis; in Allium it corresponds to the sucrose solution 0.4M to 1.0M. The osmotic pressure of the PMC in the corresponding stage is somewhat lower than that of the TCN. 6. The CPN in both TC and PMC has the highest water absorbability and swells enormously when it is treated with lower osmotic sucrose solution. The ability in the chromosome elements in the same nucleus is lower than the CPN, and that of the nucleolus the lowest. 7. The equilibrium of the surface of the CPN is in a very high tension, so that a stick with the micro-needle, the treating with dilute acetic acid, and a shock such as is given by the squeezing out of the mass of PMCs covered with the TCs, break it and the hygroscopic sur-face membrane of the CPN sucks water from the chromosomes and other surrounding substances, swells and pushes off the shrunken chromosome elements to a corner of the nuclear cavity, i.e. a state called ‘Vitalentmischungsartefakt’ by Bêlar reveals. 8. When enough water is given to the PMC, the CPN swells absorbing water and its surface reaches the cell membrane and pushing off the cytoplasm and also the secret, comes out into the medium and there expands enormously, probably until it reaches the monomolecular layer, if no inhibition is given from outside. The chromosomes follow the CPN, and loosen the spirals and elongate by themselves in the CPN, but do not dissolve in it. 9. When a part of the CPN was extruded from the nucleus into the cytoplasm it develops as a vacuole by absorbing water. 10. It is considered that the hyaloplasm of the cytoplasm is also considered to be the derivative of the CPN. The mechanism of the penetration of foreign substances such as viruses into the cytoplasm was discussed. 11. The chemical nature of the CPN is not known for certain yet, but the staining reaction, its behaviour in the sucrose solution, and the semipermeability lead us to consider that it is a certain kind of the lipopepteids. 12. The CPN in the IM prophase of the PMC of Allium odorum contains the pectic substance and callose. These carbohydrates control the expansion of the surface membrane of the CPN. 13. The behaviour of the chromosomes in the IM prophase may be controled by the condition of the CPN. 14. It was also considered that the structure of the IM prophase chromosome in vivo is to be represented by that of the fixed one under the adequate controls. 15. The phenomenon of the ‘Lichtleere’ is discussed.