Une forme tétraploïde de Crotalaria goreensis a été obtenue par traitement de graines germées et de jeunes plantules par la colchicine. Elle montre les caractéres habituels des polyploïdes et sa stérilité est importante. A la microsporogénèse, les quadrivalents ne sont pas nombreux. Les univalents sont fréquents; ils se divisent en première anaphase, restent dans le fuseau en seconde division et se transforment en micronoyaux. Les grains de pollen sont viables, mais leur taille est variable. Au niveau de l'ovule, la stérilité se marque par la production de sacs embryonnaires incomplets, par l'arrêt des tubes polliniques avant leur arrivée à l'ovule ou a l'entrée du sac embryonnaire et par l'avortement de certaines graines par suite du mauvais développement de l'endosperme. Les irrégularités méiotiques semblent responsables de la plupart de ces anomalies et de la stérilité.
Artificial hybrids between tetraploid (2n=40) Bothriochloa intermedia (R. Br.) A. Camus and both Capillipedium parviflorum (R. Br.) Stapf and C. spicigerum S. T. Blake were produced and studied. The cytology of the hybrids suggests close homology between the chromosomes of Bothriochloa O. Kuntze and Capillipedium Stapf. Each genus, however, is characterized by the unity of its morphological type and it is suggested that chromosome pairing may take place autosyndetically. Capillipedium spicigerum S. T. Blake could have originated from a hybrid between B. intermedia (R. Br.) A. Camus and C. parvilorum (R. Br.) Stapf backcrossed to the latter species.
Cytological study has been carried out on seven species of Iridaceae, distributed under four genera, namely, 1. Babiana sulphurea 2n=14 2. Tritonia crocata 2n=60 3. T. crocata Type I 2n=22 4. Tigridia pavonia 2n=26 5. Moraea iridioides var. Mcleyii 2n=40 6. M. iridioides var. bicolor 2=40 7. M. iridioides var. johnsonii 2n=20 On the basis of the data obtained and taking into account previous reports, it has been suggested that n=7 is probably the basic number for Babiana. A distinct line of evolution has been drawn for this genus, unrelated with the three other genera studied here. Tigridia pavonia shows abrupt size difference among the members of its complement and a different line of evolution for this genus too has been proposed. Tritonia crocata Type I, formerly included under Montbretia, has been observed to be cytologically allied to the genus Crocosmia. Its inclusion under the latter or its status as a member of a separate genus Montbretia, is urged. Tritonia crocata and the three varieties of Moraea iridioides show affinities in chromosome number and karyotype. A common evolutionary line had been assumed for them. Numerical and structural alterations of chromosomes in the somatic tissue have been noticed and their significance in evolution has been emphasized.
Refractometric investigations of the Golgi elements, by phase contrast illumination, were made in the hepatic cells of the white mouse, fixed in Schaffer's and Helly's fluids. Phase negative and phase positive pictures obtained by immersion in media of known RI, beginning with p-xylene (RI=1.4968) and ending with quinoline (RI=1.6161) showed that the Golgi material in the examined cells consisted of the Golgi granules and crenated Golgi rods whose location may form complicated structures similar to the Golgi net. The Golgi elements which occurred in various hepatic cells always varied in number and they differed in size and shape and their location in relation to the nucleus was also different. The Golgi material in binucleated cells is very abundant and usually equally distributed round both nuclei without special preference for either. The changeability in the location, size and shape point out not only to the dynamics of changes going on in the Golgi elements, but they indicate also the possibility of a change in the cells of the Golgi zone or the multipolarity of the zone. The multipolarity of the Golgi zone in hepatic cells is probably closely related to the metabolism of the cells or to the smaller or greater collection of inclusions in them.
1. The karyotypes of four diploid species, Ch. lineare, Ch. vulgare, Ch. rupestre, and Ch. nipponicum, were found to differ from each other in chromosome size, in the position of centromeres and in the number of satellite chromosomes. 2. Ch. lineare had the longest chromosomes, followed by Ch. vulgare, Ch. nipponicum and Ch. rupestre. 3. The chromosome complement of Ch. lineare was without chromosomes with subterminal centromeres, while the chromosome complements of Ch. vulgare, Ch. rupestre and Ch. nipponicum had two pairs of chromosomes with subterminal centromeres. 4. Ch. lineare and Ch. vulgare had three pairs of satellite chromosomes, Ch. rupestre had two pair of satellite chromosomes, and Ch. nipponicum had only one pair of satellite chromosomes. 5. The satellite chromosomes of the four species were found to be a nucleolar chromosome. 6. Species with shorter chromosomes had fewer satellite chromosomes than those with longer chromosomes. The former were presumed to be the advanced species and the latter the primitive species. Ch. lineare is presumed to be the most primitive among the four species.
Meiosis in Trivandrum materials of Cocos nucifera and Areca catechu has been described. The haploid chromosome number in both the species is found to be the same (n=16). The present study indicates need for careful karyotype analysis in both species to help in selecting suitable parents for hybridisation work.
The fine structure of the chloroplasts of various algae were investigated with an electron microscope. Materials used for the present investigation included 21 species from 7 divisions of algae. In addition to 4 species from 2 divisions which have been reported previously by the author, 25 species from 9 divisions were studied with regard to the structure of their chloroplasts. Of the 9 divisions, the Cyanophyta and Glaucophyta were found to have no chloroplasts while the others had. The chloroplasts of these latter algae were classified into several groups in relation to the lamellar structure of their chloroplasts; these groups are (1) chloroplasts with two lamellate layers, (2) chloroplasts with four lamellate layers and (3) chloroplasts with granalike structure. The Rhodophyta belong to the first group, the Phaeophyta, Pyrrophyta, Chrysophyta and Euglenophyta to the second group, and the Charophyta and Chlrophyta to the third group. These groups may be subdivided an the basis of the presence or absence of pyrenoids. Several lamellae, which are similar in their appearance to those of the chloroplasts are seen in the pyrenoids. Pyrenoids are classified into five types in relation to the lamellae and the assimilation products.
1. Some findings an the nucleic acids of Feulgen negative plants, Oscillatoria limosa, Spirogyra sp. and Marchantia polymorpha, studied by the Feulgen's staining method and biochemical procedures, are reported. 2. Cells of these plants were not stained with Feulgen's method under various conditions of fixations and acid hydrolysis, but certain amounts of DNA were isolated biochemically from cells of these plants. Isolated DNA gives positive reaction with Feulgen's and Dische's tests in vitro. Absorption maximum of the Feulgen's color at pH 2.28 with DNA from these plants, locates at 565mμ. 3. Maximum of UV-absorption curve of DNA, isolated by Schmidt and Thannhauser's method from above plants, situates at 260mμ in all cases, and no significant difference among UV-absorption curves of DNA from these plants and calf thymus, has been found. UV-absorption maximum of DNA, isolated by the procedure of Ogur and Rosen using hot PCA, however, locates at 268mμ. Similar results are obtained when calf thumus and fish sperm-DNAs have been heated with hot PCA. 4. Nucleic acids and other P-containing substances in cells of these Feulgen negative plants are determined quantitatively. Especially, DNA and RNA have been determined by several methods for the estimation of three major constituents of nucleic acids. Mean values of DNA content per cell in Oscillatoria limosa, Spirogyra sp. and Marchantia polymorpha are 8.1, 2.9 and 0.48×10-9mg respectively. Causal analyses of Feulgen negativity in histochemical preparations will be discussed in another paper.
1. The development of zoospores and their liberation has been studied in Achlya aplanes Maurizio var. indica both in living and fixed conditions. 2. Four principal stages in the development of the sporangium in living condition were observed. The first stage consists of the inflow of protoplasm resulting in the formation of sporangium initials and the formation of basal septum, followed by the stage of preliminary division, the homogeneous stage and the stage of final division and formation of zoospores. 3. The zoospores after liberation undergo a period of rest, after which they germinate directly by germ tubes. Absence of any swimming stage was confirmed. 4. Studies in fixed condition regarding the developmental stages, confirm the findings made during living condition. No nuclear division was observed in the sporangium.
Some interrelations between the macronucleus and cytoplasm in the gymnostome ciliate Chlamydodon pedarius have been studied by means of the electron microscope. The aggregates of the small particles about 100Å to 200Å diameter located in the cytoplasm adjacent to the nuclear envelope are seen to be continuous with the loose and collapsing structures of the nucleoli through the pores of the nuclear envelope. The nucleoli are located beneath the nuclear envelope with the intercalary zones, through which the strand-like connections are found to be traversing from the nucleoli to the nuclear extrusions. The perinuclear cytoplasm of the macronucleus could be interpreted as a site of the organization of mitochondria or at least mitochondria precursors with the efficient materials from both the macronucleus and cytoplasm. The anterior part of the old macronucleus shows that a certain dissolving of the nucleolar structure might probably concur with a shrinkage of the nuclear membrane and it causes the extrusion of the nucleolar materials into the cytoplasm. The electron micrographs of the sections through the right and left plane of the macronucleus show that the contours on the right and left. surfaces of the macronucleus are dissimilar, in addition to a structural difference in the anterior and posterior halves of the macronucleus. These differences suggest that the morphologically and the physiologically complex nature of the cytoplasm might necessitate the local specializations of the phenomena in the macronucleus.
A hypertriploid subline of Ehrlich ascites tumor, having a modal chromosome number at 65, was discovered in this laboratory. This new subline shows a much higher degree of virulence than the fast-killing hypotetraploid subline which has been known to be the most malignant of all Ehrlich ascites tumors. By the chromosome morphology study, it is further substantiated as a subline of Ehrlich ascites tumor. The biological and biochemical characteristics of this hypertriploid subline have been investigated. Its pattern of respiratory activities is different from other Ehrlich ascites tumor sublines reported.
The process of development and cytology of the sexual organs of Achlya aplanes Maurizio var. indica was studied and found to be essentially the same as that of other members of the family Saprolegniaceae. There was only one nuclear division in the oogonium, and the decrease in the number of nuclei was due to degenaration. Present investigations clearly established the process of fertilization in the material studied.
To elucidate the role of cytoplasmic structures in determination of the position of new cell wall, relatively mild centrifugal forces (3550 g or less, 15 minutes) were exerted on the stamen hair cells of Tradescantia reflexa. Observations were made all in vivo. Cinematographic technique was employed in some cases. After centrifugation, the spindle returns to the center of the cell with simultaneously proceeding elongation of the spindle itself and poleward separation of the daughter chromosomes. The process of recovery from the effects of centrifugation is almost the same without regard to strength and direction of the centrifugal force and whether the cell is centrifuged once, twice or three times successively to opposite directions. The cytoplasm in a dividing cell is considered to be specially differentiated to maintain the shape and function of the spindle and to determine the mitotic axis and the cytokinetic plane. The spindle is considered to be held at its right position in the cell by the following manner that it is enveloped with a cytoplasmic layer (spindle envelope), which is connected to some differentiated pattern in the cell cortex by the polar plasmic strands, the phragmosome and other cytoplasmic strands. The returning movement of the spindle after centrifugation is considered to be brought about by movements of this cytoplasmic system. Abnormal partition walls were formed in some few cases after repeated centrifugation. These abnormalities seem due to general enervation of the cells by accidental damages in the buds during centrifugation, rather than due to the direct effect of centrifugal forces. By treatment of cold-ethanol-fixed pollen mother cells of Lilium longiflorum with hydrogen peroxide and detergent, the cytoplasmic envelope of the spindle can be distinctly visualized.
1. Several staining and histochemical properties of the components of Golgi complex of the fibroblasts cultured in vitro and the ascites tumor cells of the mouse were studied. 2. When examined with phase optics, the Golgi complex of the living fibroblast consists of canalicules and filaments, while that of the tumor cell is composed only of filaments. The filaments are finer than the mitochondria and blurred in outline. Since the walls of canalicules show the same staining and histochemical properties with the filaments, the canalicules are thought to belong to a category of filaments, which are either dilated locally or are dilated whole-length. 3. The Golgi filaments (the word is used in the broad sense, as indicated above, in this and the following sections) are blackened more readily than mitochondria by the addition of osmium tetroxide. They are stained red with Altmann's acid fuchsin as mitochondria. 4. Janus green stains the Golgi filaments as it does mitochondria. In the fibroblast, a higher concentration of the dye is evidently required to stain the Golgi filaments than mitochondria. 5. The Golgi filaments visualized by blackening with osmium, by staining with acid fuchsin and by vital staining with Janus green are distinguished from mitochondria, as the former are more slender and less smooth in outline than the latter and are possessed of a characteristic of gathering in the vicinity of the nucleus. 6. The Golgi filaments are stained vitally with neutral red, and vitally and metachromatically with methylene blue, trimethylthionin and toluidine blue. 7. The ground substance of the Golgi area is often darker or lighter under the phase microscope than the remainder of the cytoplasm. It becomes darkened with osmium and is stained post mortem with acid fuchsin and intra vitam with trimethylthionin. 8. The Golgi filaments in the both types of cells are not stained with iron hematoxylin and resorcin-fuchsin. They do not react positively to the acid hematein test, nor to the periodic acid-Schiff and alkaline phosphatase techniques. They are weakly stained with sudan black and Nile blue in the calcium-formol fixed materials.
The morphology of the somatic chromosomes and meiotic behaviour of chromosomes in Phymatodes scolopendria (Burm.) Ching and P. nigrescens (Bl.) J. Sm. is described. In both species the chromosome number is n=36 and 2n=72. The somatic chromosomes are characterised by the predominant occurrence of subterminal centromeres. The ratio of length of the shortest and longest chromosomes in both species is about 1: 2.2. The length of the chromosomes ranges from 2.9-6.5μ in P. scolopendria and 2.4-5.2μ in P. nigrescens. Meiosis is fairly regular in both species. In P. nigrescens the tetrad nuclei, in some of the sporangia, fuse together to form large tetraploid nuclei which immediately undergo ‘secondary meiotic’ division and show much irregularity in this division. The authors wish to convey their sincere thanks to Dr. I. Banerji for his kind interest in this work.
1) The appearance of follicular fluid and tissue fluid in the ovarian stroma after submaxillariectomy was studied in the guinea pigs. 2) The submaxillariectomy causes clotting of follicular fluid and tissue fluid in the ovarian stroma. In other words the secretion of the submaxillary gland presumably contains the anti-coagulate enzyme for the follicular fluid and tissue fluid in the ovarian stroma. 3) The antrum formation in the follicles may be due to the adhesion of clotted follicular fluid to the ovum. 4) The cause of aberrant ovarian follicles in the submaxillariectomized guinea pigs may be due to the modification of primordial ova by the adhesion of clotted tissue fluid in the ovarian stroma. 5) From the results of the present study, it may be suggested that an atrophic change of the submaxillary gland is one cause to produce the twins from the aberrant ovarian follicles.
1. The nature of submaxillary glands and the cause of deterioration of the tubules in the testis of guinea pigs were studied. 2. The cause of deterioration in the testis may be due to the clotting in the intercellular substances of the germinal epithelium as a result of the submaxillariectomy. 3. The atrophic change of germ cells in the testis of the submaxillariectomized males may be due to the deterioration of intercellular substances in the germinal epithelium. 4. The secretion of submaxillary gland in the male guinea pigs seems to contain the anti-coagulate enzyme for the intercellular substances of germinal epithelium.
Mitotic spindles of Tradescantia cells were irradiated with an ultraviolet microbeam about 2μ in diameter and its effects on the mitosis were investigated in in vivo observations. 1. A complete suppression of the spindle development occurs, when a polar cap is irradiated in its very young stage and a partial suppression appears when a polar cap is irradiated in its slightly later stage from its appearances. 2. In a complete suppression of the spindle development, a restitution nucleus appears, while in a partial suppression of the spindle a half spindle develops at the intact pole side, inducing blocking and sticking of the chromosomes at the irradiated pole side. When the half spindle transforms into a phragmoplast, both daughter chromosome groups are pushed by the growing of the phragmoplast to the irradiated pole side. 3. Other mitotic aberrations, such as daughter nuclei unequal in size, those with vacuoles, reversion of prophase nuclei into resting ones and occurrence of sticky chromosome bridges are obtained in cells irradiated in various mitotic stages. 4. From the results of UV microbeam irradiations on the polar caps or the spindle poles, their roles and submicroscopic structure were discussed in connection with the mechanism of mitosis.