Colchicine has been successfully employed for the first time in inducing the formation of polyploid nuclei in the green alga Sphaeroplea annulina (Roth) Ag. The haploid chromosome number was determined to be 16. Greatly deficient, aneuploid and polyploid nuclei were found to be capable of survival and repeated mitoses in the cytoplasm of the coenocyte.
Es wurden die Chrornosomenzahlen einer Reihe von Acanthaceen bestimmt. Bei einigen günstigen Objekten gelang es, die Struktur der Pachytänchromosomen zu beschreiben. 1. Die Haploidzahlen wurden festgestellt von Thunbergia alata (n=9), Strobilanthes isophyllus (n=10), Hernigraphis repanda (n=14), Ruellia devosiana (n=17), Aphelandra aurantiaca (n=14) Aphelandra chamissoniana (n=14), Peristrophe salieifolia (n=21) Hyphoesthes phyllostachyi (n=11-13), Thyrsacanthus rutilans (n=21), Fittonia argyroneura (n=18), Fittonia gigantea (n=18), Fittonia verschaffeltii (n=18), Justitia coccinea (n=16), Beloperone guttata (n=14). 2. Hinsichtlich der Struktur ihrer Pachytänchromosomen gehören die untersuchten Acanthaceen zu den sogenannten partiell-heterochromatischen Objekten. 3. Die geringste Heterochromasie findet sich bei Beloperone, die stärkste bei Aphelandra, Thyrsacanthus and Fittonia. Stets ist das Heterochromatin bevorzugt beiderseits der Insertionsstelle zu finden. Letztere liegen meist median bis submedian. 4. Die Spiralisation der Pachytänchromosomen ist in alien Objekten vorhanden. Ihre Größe entspricht dem Maße der Heterochromasie. Stets finden sich auch in den sogenannten euchromatischen Chromosomenenden kleinere and größere Mengen von Heterochromatin. 5. Es gelang, die Pachytänchromosomen von Strobilanthes isophyllus and Beloperone guttata vollständig zu identifizieren. Bei anderen Objekten konnte ein Großteil der Chromosomen morphologisch erfaßt werden.
1. The present investigation furnishes cytological information on three pyrrhocorid bugs, Antilochus conqueberti, Scantius volucris and Pyrrhopeplus posthuanus belonging to the sub-family Pyrrhocorinae. 2. The diploid number of chromosomes in the three species, as determined in the spermatogonial metaphase, is as follows: Twenty-seven in Antilochus conqueberti, nineteen in Scantius volucris and twenty-four in Pyrrhopeplus posthunus. 3. Antilochus conqueberti and Scantius volucris have each an XO type of sex mechanism while Pyrrhopeplus posthunaus has two Xs which fuse, during anaphase I, to from a single body. This behaves as such during the second division. 4. The general course of meiosis is fairly constant in all the three species. In Scantius volucris and Pyrrhopeplus posthunaus the growth of the auxocyte starts right in the contraction stage. This, consequently, results in the absence of the regular zygotene and pachytene in Scantius volucris. 5. The first division is reductional for the autosomes and equational for the sex chromosomes while the reverse is true of the second. 6. The nature of the association of the sex univalents from anaphase I onwards, ini Pyrrhopeplus posthunaus, has been discussed.
The ribonucleoprotein particles isolated from the rat liver microsomes were observed electron microscopically. The sprayed and shadowed specimens illustrated the spherical or polygonal particles 100200Å in diameter, which were decomposed by incubation with RN ase and trypsin to smaller fragments. These ribonucleoprotein particles, when fixed with OsO4 and sectioned, had a light core and dense ring around them, though the existence of homogeneously dense particles or the particles with denser core and light ring can also be ascertained. Comparing these findings with these of TMV or chromosomes, it was estimated that there may be two sort of nucleo-protein, that is, stable NP (covered type) and labile NP (covering or mixed type) and the former is usually covered by the latter. The authors wish to express their thanks to Prof. Kyugo Sasakawa and Prof. Katashi Inouye for his invaluable advice in our experiments, to Prof. Namio Shinke, assistant Prof. Keinosuke Kobayashi, Drs. Mituo Ogura, and Sadahiko Okamura for their helpful discussions.
The cytology of a number of genera belonging to the tribe Scilleae was investigated. Six genera and 68 species and varieties were previously unknown cytologically. The chromosome number is also reported in some species belonging to 3 genera not included in the Scilleae. The genera which were investigated, cytologically for the first time, are Albuca (n=9), 10), Thuranthos (n=10), Pseudogaltonia (n=12), Rhadamanthus (n=10), Drinzia (n=9, 10) and Schizocarphus (n=14). The relationships between the genera were pointed out where possible. The original basic chromosome number for the tribe Scilleae has been postulated as being n=5.
1. An artifical key to the genera of the subtribes Ischaeminae, Rottboelliinae, and the Maydeae is given. 2. A review of the cytology of these subtribes, including chromosome number and meiotic behavior whenever available, is recorded 3. Of the 35 genera in these subtribes only 19 have been studied and two of these, Lasuirus and Hackelochloa, are reported here for the first time. 4. Three basic numbers, five (ten), seven and nine, have been found in each of the subtribes with polyploidy occurring in each of the basic number groups. 5. A brief discussion of the phylogenetic patterns of the subtribes it presented. Both cytological and morpholgical factors are considered but it is decided that it is still premature to make definite conclusions since the samplings of the materials in these subtribes are so inadequate. 6. It does, however, appear quite likely that the genus Ischaenmum is of fundamental importance in this problem and that a thorough understanding of this genus may furnish a key to the overall problem.
In the present investigation, the migration of the colloidal substance in the motor tissue of Mimosa pudica L. was studied from the cytophysiological view-point. The results obtained are summarized below. 1) Author's new technique, Müller-water blue method, is found to be excellent to examine the motor tissue before and after receiving stimulus. 2) By fixing the motor tissue with Regaud's fluid, Champy's fluid, neutral formalin and Milovidnov's fluid, each in combination with water blue or neutral red staining, the differences in the motor tissue-cells before and after receiving a stimulus can be observed. These differences are summarized as follows. 3) By the bending movement, the colloidal substance in the central vacuole permeate towards the intercellular spaces. This migration is thought to be accompanied with the migration of potassium salts. 4) This phenomenon suggests that the permeability of cytoplasm against colloid and potassium increases at the bending movement and its recovery.
Various cellular organella, especially the centrioles, the Golgi body, and the spindle body in regard to their activity in mitosis were studied under the phase contrast and electron microscopes and herewith a new viewpoint of mitotic mechanism, a neo-extension-fiber theory was offered. 1. The centriole of the mitotic cells as observed under the EMS consists of following three components, namely, a central clear sphere, b. shell zone with high electron density, and c. centrosomal capsule zone (C1 internal capsule and C2 external halo). 2. The centriole of the interkinetic cells has a cylindrical form, whose transverse section coinciding the structure just described in 1, whereas in longitudinal section it was revealed that the cylinder (120-160mμ in diameter and ca 350mμ in length) consist of nine parallel running canaliculi sur-rounding clear space in the center. Each canaliculus has a size of 20mμ in diameter having a sheath of RNA-like substance with high electron density. The further extension of these canaliculi going out from the RNA sheath, run around the centrioles and form a net-work corresponding the canaliculi of the Golgi body (Golgi protofilaments according to our nomen-clature), which may be demonstrated most evidently in plasma cells. The fact also explains the reason why the parallel running Golgi canaliculi or protofilaments are enumerated usually 4-6 in ultra-thin sections and maximally nine. 3. In mitosis, nine canaliculi intermediating two centrioles develop particularly and form the skeletal structure of the spindle body. These correspond to the nine neo-extension- fibers of the spindle body of animal cells observed under the phase contrast microscope. Therefore, neo-extension-fibers here defined correspond to nine continuous fibers between the centriole; thus the previously proposed development of the connective fibers between the paired kinetochores has been abandoned. These nine neo-extension-fibers work always as extending craft through the period of the mitosis. This understanding postulates the rise of half spindle fibers (between centrosomes and kinetochores) probably from the centrosomes in a different way as the neo-extension fibers. 4. Therefore, the chromosomes of the mitotic animal cells arrange on the equatorial plate supported by the half spindle fibers and their separation is taken place through the elongation of the neo-extension-fibers principally. In this case, the kinetochores of the chromosomes connect with the half spindle fibers without any direct relation to the neo-extension-fibers and play a role as a tonicity center for the neighbouring organella, as it is demonstrate-under electron microscopic pictures. 5. As the neo-extension-fibers in respect to thier structure are induced from the fundamental structure of the centriole, they have nothing to do with the mitosis of plant cells. The essential characteristics of the animal cells differentiating from the plant cells in the course of the mitosis may be attributed to the existence of these neo-extension-fibers. Therefore, we have reached to a view-point which enable us to classify animal and plant cells as refer to the structure of the mitotic organella, the centrioles.
1. The development of the male gametophyte in Tradescantia canaliculata the cult. No. 88, 14, 1, a descendant of the plant bombed at Hiroshima 1945, was investigated. Most of the studies were performed in vivo. 2. The shape of the M.S. is a quarter of a sphere, having two semicircle plain side walls and one spherical dorsal wall. The nucleus generally occupied the center of the cell. Two large vacuoles are found on both sides of the nucleus in the cell mentioned above, the a-case M.S., but in some rare cases the nucleus occupies one corner of the cell and a large vacuole the other corner, the b-case M. S. 3. The 1st cell division in the a-case M. S. results in a large V.C. and a small G. C., the latter penetrating later into the cytoplasm of the former, but in the b-case such special development was not shown. The data show that the divided sister cells have no specialities by themselves. 4. The substance forming the phragmoplast was traced. It secreted the wall substance and the remnant contains lecithin which plays an impor-tant role in the vacuole formation . 5. The nuclear granules appear in the nuclei and are secreted out into the cytoplasm, where they develop into vacuoles, absorbing water. 6. The maturation of the P.G.s was followed and it was found there are several grades in the development in the grains in one and the same anther which reached the last stage of development. 7. The germination of the P. G.s was traced in vivo. The development of the vacuoles in the grains and their position in the grain play some role in the development of the pollen tube, especially in the determination of the point from where the tube comes out from the grain and also of the number of the tubes. 8. In the most germinated P.G.s the G.C. and the N.V.C. stayed in the grain proper, and did not move into the elongated pollen tube. 9. The growth of the C.S.H. was described. 10. The role that vacuole formation plays in the growth of the cells in plants was discussed. The vacuoles originating from the nuclear granules cause the cell growth and the expansion of the surface area of the cell, but the growth of the vacuoles is not the result of cell growth. 11. Non-transportation into the pollen tube of the G.C.s and of the N.V.C., especially of the former, must be the cause of the absence of the embryo in the seeds ; while the penetration of the pollen tube into the style, even when not accompanied by any nuclear mass may give the stimulation for the execution of the growth of the ovary and also of the ovules which are parts of the body of the mother plant, and would be withered off if certain stimuli to regain the vital energy were not given.
This is a report on the somatic chromosomes and meiotic division in Mangifera foetida and M. caesia, two Malayan species of Section II of the genus. Observations show that the species have the same chromosome number n=20 and 2n=40, as has been found previously in three other species of Mangifera, indicating thereby a stability in the chromosome numbers in the genus, as in the case of Citrus and other genera. Meiotic division in M. foetida is regular, with regular pairing and anaphasic disjunction showing 20 bivalents in metaphase. Similarity in chromosome number and pollen morphology in different species of the genus suggests close compatibility during hybridization and stock-scion relationship, if other species are used as stock for the common mango, Mangifera indica.