(1) The phenotypes of various miniatures and duskies, m1, m4, m7. m10, dy1, and dy4, found in D. virilis, have been studied by measuring the wings of female flies as indicated in Fig. 3. The absolute lengths have been reduced to lengths, relative to the intercostal length. The results are shown in Table 1. (2) m1 gives by far the strongest effect, the effect of the other miniature genes decreasing in the order of m1, m7. m4, m10; the effect of dy1 is slightly stronger than that of dy4. (3) All the mutant genes are incompletely recessive to the wildtype; the heterozygotes are more or less different from both homozygotes and wild-type. The degree of this difference is roughly parallel to the degree of divergence between the homozygotes and the wild-type. (4) Of the compounds of the mutant genes, those with m1 are all intermediate between m1 and the homozygote of the other gene; m4/m7 and m7/m10 are nearly identical with m4/m4 and m10/m10 respectively, while m4/dy1 and m4/dy4 depart to a smaller degree from the wild-type than do the respective homozygotes, m4/m4, dy1/dy1 and m4/m4, dy4/dy4, from the latter. These findings indicate the allelism of the different kinds of miniatures (or duskies) and are non-allelism of miniature and dusky. (5) From m7/dy1 females, a few crossover wild-type males have been obtained, the recombination value being 0.115 percent in one series of experiments and 0.0336 in the other series. (6) Thus, miniature and dusky are mutants of different loci very closely linked and having similar characters. (7) The relation between miniature and dusky is compared with that between achaete and scute in D. melanogaster. (8) Since the recombination values mentioned above probably represent about the lowest possible normal value, they can be made the basis from which the number of gene loci separable by crossing-over in this species may be calculated. This is about 1480 for the X-chromosome and 8000 for the whole haploid chromosome set, according to one series of experiments, and about 5060 for X and more than 25000 for the whole set, according to the other. The estimate given first roughly coincide with those previously made for D. melanogaster and are probably more accurate.
1) The effects of KCN are similar to those of ammonia and NaOH. A strong vacuolization in the cytoplasm and associated dehydration phenomena of the cell elements take place, and di-diploid nuclei and bi-nucleate cells are obtainable after the replacement of the medium with water, but the range of effective concentrations seems to be narrower than in ammonia while it is nearly equal to the case of NaOH. 2) Sodium azide. malachite green, au amin and tannin cause coagulation of the cell as a whole which takes place preceded by cytoplasmic vacuolization and accompanying dehydration phenomena in the cell. Binucleate cells and di-diploid nuclei are obtainable only in a few cases where the medium is replaced with water at the first stage toward coagulation similarly to the case of heavy metal salts. 3) Ethyl urethan solutions of high concentrations also cause coagulation of the cell as a whole, preceded by vacuolization and dehydration phenomena in the cell. In some cases (in 2%, solution) the coagulation of the chromosomes is reversible, and the chromosomes can undergo nuclear reconstruction process resulting in the formation of a di-diploid nucleus and bi-nucleate cell. In lower concentrations the vacuoles in the cytoplasm become also enlarged, but the mitotic process proceeds normally to the end. 4) Methyl sulphonal is only slightly soluble in water, and even in the saturated solution mitosis proceeds quite normally, no abnormal cells and nuclei being obtainable. 5) Coal tar extract acts on cells in a similar manner to the cases of alkaloids, narcotics, neutral salts and ammonia, and di-diploid nucleus and bi-nucleate cell are produced when the medium is replaced with water. 6) Under the influence of colchicine, such a strong vacuolization in the cytoplasm as observed in the case of ammonia and neutral salts does not take place, but the spindle decreases in volume, and the di-diploid nuclei and bi-nucleate cells are formed without being made any aftertreatment. The most remarkable changes observed are the suppression of the process of mitosis which may occur at any stage after metaphase and the nuclear reconstruction process which takes place at the stage at which the mitosis becomes suspended. The affecting manner of colchicine differs fundamentally from the cases summarized above from 1) to 5) in the points that the suppression of the mitotic process is not connected with the cytoplasmic vacuolization, and that the untimely occurrence of the nuclear reconstruction process chiefly due to the intracellular re-distribution of water. 7) Acenaphthene shows no effect on mitosis, the mitosis proceeds quite normally to its end, probably depending on the difficulty in solubility in the case of water solutions and in penetrability in the case of liquid paraffin used as solvent. 8) Sodium cacodylate affects cells in a similar manner to the case of colchicine, and di-diploid nuclei and bi-nucleate cells are obtained without the replacement of the medium with water.
1) Under the influence of high temperatures (32.5°C43.5°C in the case of leaf epidermis and 47°C53.5°C in the case of petal cells), the enlargement of vacuoles in the cytoplasm and the increase in refractivity of chromosomes and the decrease in volume of the spindle are brought about and di-diploid nuclei and bi-nucleate cells are formed after re-exposure to the room temperature, just in the same manner as in the case of neutral salts, ammonia and etc. 2) Under the influence of low temperatures (about -4°C-6°C), the mitosis ceases to proceed, and the chromosomes increase in refractivity. After re-exposure to the room temperature, most of the mitoses continue to proceed on normally, and only in a few cases di-diploid nucleus is formedIn the case where di-diploid nuclei are formed, the dehydration phenomena taking place in association with the vacuole enlargement in the cytoplasm are recognizable. 3) In some cases the asymmetrical division, the uni-polar division and a pseudo-tripolar division are observed.
In the cytological studies of the geographic races of Lymantria dispar, GOLDSCHMIDT ('17, '20, '32) pointed out racial size difference of chromosomes indicating that the amount of chromatin is in an inverse proportion to the strength of sex-races. Close examination of his data revealed some questionable points worthy of study. The reinvestigation was here undertaken by the authors with material coming from twelve localities. The races coming under study are treated as follows: the weak race from Sapporo, the neutral race from Kyoto, Ayabe and Kumamoto, and finally the strong race from Aomori, Tokyo, Matumoto, Misima, Nagoya, Gifu, ogaki and Maibara. The haploid number, 31, was obtained in the study of the primary and secondary spermatocyte throughout the geographic races under observation. The diploid number, 62, was observed in the spermatogonial metaphase of one of the races. The chromosomes of the haploid group are round or oval in outline and vary in size very slightly forming a well graded series in the diminution of size. It was found to be practically impossible to group the chromosomes as large, medium and small ones, as done by GOLDSCHMIDT. The comparative study of chromosomes of the geographic races leads to the conclusion that the chromosomes of the studied races are fairly identical in their general appearance, especially in regard to the size of chromosomes, and that there is detected no essential morphological difference in the chromosomes among the races obtained from the different localities and also among the different sex-races. In the light of these studies it must be concluded that GOLDSCHMIDT'S contention that the chromosomes of the weak, neutral, and strong sex-races of Lymantria dispar show perceptible size differences resulted from mistaken observation and irregular technique. The error apparently resulted from: (1) a confusion between the secondary and. primary spermatocytes; and (2) varying degrees of decolorization in the staining process, producing the variation of chromosome sizes.
1) Somatic chromosomes and meiotic divisions of 97 F4 individualsn of Paraixeris denticulctta and Crepidiastrum platyphylluin, were examined. 2) In many individuals the somatic chromosome number was 10.. Only three had 11 chromosomes. In the root-tips of four individuals polyploid cells were observed besides the diploid ones. In some individuals. new types of chromosomes were observed. 3) In the meiotic division some individuals had bivalents only. But in the others multivalents or prematurely separating bivalents were observed in abundance. The forms of the multivalents and the component chromosomes of them were quite variable even in one individual. More multivalents were observed in the earlier diakinesis than in the metaphase. The writer wishes to record his cordial thanks to Prof. SINOTO of the Tokyo Imperial University under whose direction the work has been carried out. Thanks are also due to Prof. OHUYE of the Matuyamakotogakko who afforded him much facilities during the progress of the work. The expense was partly defrayed from the Japan Society for the Promotion of Scientific Research to which the writer wishes to express his gratitude.
The karyotypes of twenty-five genera including thirty species in the Palmae were analyzed from the view point of karyotype alteration (cf. Tab. 1). Various basic numbers in Palmae seem to be originated from the eight chromosome type, that is, 8→16→18→19, but an exact phylogenetic line can not be drawn simply by the basic number or karyotype. Four karyotypical lines, Liliaceae→Agavaceae→Palmae, are presented by the writer's observation: 1) Eucomis, Hosta→Yucca-Agave, 2) Dianella →Phormium→Cocos, 3) Ophiopogon→Nolina→Trsthrinax, 4) Dracaena→Phoenix, Livistona, Sabal and Oredoxa (cf. p. 183). In short the writer clearly ascertained the phylogenetic affinity between Agavaceae and Palmae. This conclusion supports th-e HUTCHINSON'S opinion and unfavours ENGLER's system of monocotyledons. Here the writer reminds a dynamic system of late Professor HAYATA. Although the karyotype seems to be more essential and changelesss characteristics than the other external morphology, the so-called karyotype or chromosome morphology is also conditioned by ecological environments as well as the other phenotypes. Some karyotypical characters in the tropical plants are suggested here, that is, chromosome sizes and polyploidy with special reference to gigas forms and winter hardiness. Acknowledgment. In conclusion the writer wishes to express his sincere thanks to Professor SINOTÔ for his kind advice and valuable criticism throughout the course of the work. Thanks are also due to Professor HONDA of the Tokyo Imperial University and to Professor NAMIKAWA of the Kyoto Imperial University for granting the use of the materials.
1. The difference of the staining behavior of nucleoproteins contained in chromatin and ergastoplasm or nucleoli against several basic dyes (pyronine-methyl green, thionine, etc.), which has recently been discussed by the author (1948a, b, c), may be distinguished terminologically as follows: chromatin is eubasophile while ergastoplasm and nucleoli are heterobasophile. 2. The morphological changes of heterobasophile ergastoplasm (ribonucleic acid) and cytochondria of liver cells under normal and pathological conditions have been classified into four main types and described in detail. The important characteristics of these types consist in appearance, disappearance, and distribution of the ribonucleic acid and relative quantity and dimension of the cytochondria. The four types may, for convenience sake, be called 1. normal type, 2. reacting type, 3. mortal type or “catastrophe”, and 4. recovering type. 3. The nucleotide and protein natures of ergastoplasm and their implications in cell metabolism, the localization of ribonucleic acids in the cytoplasm, the relation of the morphological changes of ergastoplasm and of cytochondria to pathological consumption of body proteins, and the mechanisms of pathological enlargement of cytochondria have been discussed. Lastly, it is my pleasant duty to express my hearty thanks to Dr. O. MINOUCHI who led me into this field of cytology always helping me with very instructive and valuabe advice throughout the course of this study. I am also indebted to the members of Medico-Biological Institute of Minophagen Pharmaceutical Co., and especially to Messrs. I. SATO, Zoölogical Institute of Kyoto University, and T. HAMA, Zoölogical Institute of Tokyo University, for their kind assistance and criticism.
1. The crystals in the aleurone grains are not of pure protein nature; they consist of protein substances and oil, probably forming a kind of symplex. When the oil is separated from the crystal the crystal is denaturated, so that it was considered that the oil must be the mother liquid of the crystal and the oil molecules connect the protein molecules or micelles of the protein and keep their crystal nature. 2. The aleurone vacuoles are derived from the nuclear granules. The latter were extruded from the nucleus and developed to be aleurone vacuoles, as they absorb water in the cytoplasm. The vacuoles show the reaction of oil to the osmium vapour as well as Sudan III, and also the reaction of protein substance to Millon's reagent and other protein tests. The concentration of the lipo-protein in the vacuole increases by and by, and then at first small crystals appear in the vacuole, later they aggregate together to form one or a few crystals in a vacuole. 3. Some structure of protein nature such as nucleolus are formed in the nucleus and remain in it, but some others such as nuclear granules relating to the aleurone vacuoles are extruded into the cytoplasm and results in the formation of lipo-protein crystals. 4. It was discussed that the nucleus is the organ of syntheses. 5. Many substances which are recognized as the products in the cytoplasm are considered here as of the nuclear origin. The writer's hearty thanks are due to Prof. FUJII for his kind advice in the course of the investigation. The expence of carryir.g out this study was partly defrayed out of a grant from the Department of Education, to which the writer's best thanks are due.
Chromosome numbers of some species in Pandanus, Sparganium and Tzypha are reported, as given in the following table. Basic number is 15 in both Sparganiumz and Typha and that of Pandanus remains undecided. Somatic chromosomes are generally of short rod- or dot-shaped in all species studied.
1. The ripe unfertilized egg of Oryzias can be activated with direct current. The breakdown of the cortical alveoli and subsequent elevation of the chorion begin at the anodal and the cathodal sides. 2. Reaction time for the breakdown of the cortical alveoli and the propagation of the cortical change indicate that there is a gradient of excitation-conduction in the unfertilized egg. It is the highest at the animal pole and the lowest at the vegetal pole 3. Unfertilized eggs treated with narcotics (phenyl urethane and chloretone) pare rendered incapable of cortical response upon subsequent electric stimulation. The effect of narcotics is readily reversible.