CYTOLOGIA
Online ISSN : 1348-7019
Print ISSN : 0011-4545
Volume 5 , Issue 1
Showing 1-13 articles out of 13 articles from the selected issue
  • The history of the chromonemata in mitosis of Tradescantia reflexa Raf
    B. R. Nebel
    1933 Volume 5 Issue 1 Pages 1-14
    Published: December 30, 1933
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The history of chromonemata in mitosis of T. reflexa is briefly summarized an pp. 4-5. As the chromosomes spread out in telophase four chromonemata become visible instead of the two of anaphase. They pass thru interphase without anastomosing and without much dislocation; occasionally at resting stage pairs of chromonemata may be observed, their members running parallel for some distance but mostly the chromonemata run in single paths. Early prophase shows 4n chromatic tracts in each of which two chromonemata are paired, the spirals being shoved into one another closely. In spiral prophase pairs of pairs of chromonemata are arranged into a group of four and the metaphase chromosome is thus essentially established. Later prophase involves only an increase in quantity and change in PH of the matrical coatings of the chromonemata, and lateral polarization of the materials of the chromosome which is believed to be essential for the reproduction of the (invisible) gene thread. At no stage in mitosis do chromonemata entangle.
    Discrepancies between the observations presented above and those of other authors is laid to two main reasons: acid fixation without proper pretreatment and the dif iiculty of interpreting refraction images.
    The author is indebted to Dr. L. W. SHARP and Dr. C. L. HUSKINS for suggestions and criticism.
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  • Eva R. Sansome
    1933 Volume 5 Issue 1 Pages 15-30
    Published: December 30, 1933
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Some of the progeny of the previously described hybrid with an association of 6 chromosomes were studied cytologically.
    Two plants were found to be trisomic and structurally hybrid, one showed normal bivalent pairing and was fertile, one had an association of six and was three quarter sterile, like the parent plant, and two had a new association of 4 chromosomes. The relationship between the new association of 4 and the original association of 6 is discussed.
    The frequent observation of “figure-of-eight” configurations in the association-of-six forming hybrid led to the prediction that plants with associations of four would occur amongst its offspring. Since the present observations fulfil these predictions, they afford genetical evidence that segmental interchange between otherwise non-homologous chromosomes has occurred as the result of crossing-over associated with chiasma formation in an interstitial homologous segment.
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  • Willem Eduard de Mol
    1933 Volume 5 Issue 1 Pages 31-65
    Published: December 30, 1933
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    1. In chronologischer Reihefolge sind zuerst, summarisch und in Zusammen zu einander, besprochen worden: die Untersuchungen vor und nach dem Jahre 1923 verrichtet betreffs der Entstehung anormaler Pollenkörner, in der Hauptsache bei Hyazinthen, Tulpen und Narzissen.
    2. Bei Hyacinthus orientalis und andern Species des Genus Hyacinthus kann unter bestimmten äußern Konditionen verursacht werden, daß die meiotischen Teilungen unregelmäßig verlaufen, wodurch Pollenkörner, wohl oder nicht fertil, mit einer verminderten, doch besonders mit einer erhöhten Anzahl Chromosomen entstehen.
    3. Ebenso kann bewerkstelligt werden, daß die jungen Pollenkörner mehr oder weniger embryosackartig herauswachsen.
    4. Die Hyazinthenzwiebeln haben in etlichen Fällen eine Behandlung erfahren, wodurch beide Anomalien aufgetreten sind.
    5. In dieser Mitteilung ist ausführlich auf derartige, komplizierte Fälle hingewiesen, sowie auf die Tatsache, daß der Verfasser sie erst nach dem Jahre 1923 verstanden hat.
    6. Jetzt entspricht seine Anschauungsweise über das Entstehen der anormalen Pollenkörner und was damit zusammenhängt, prinzipiell am meisten der Meinung SAKAMURAS und STOWS.
    7. Im Gegensatz zu den Hyazinthen sind bis jetzt bei Tulpen und Narzissen nur Pollenkörner gefunden worden, anormal geworden-wenn sie dies waren-durch den unharmonischen Verlauf der Meiosis.
    8. Auf die Bedeutung des Zurentwicklung-kommenlassens von Pollenkörnern mit einer erhöhten Chromosomenzahl ist hingewiesen worden im Zusammenhang mit dem Entstehen der triploiden Nachkommen aus diploiden Eltern.
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  • Influence of temperature upon the growth of fibroblasts in coverglass cultures
    Sakuzi Kodama
    1933 Volume 5 Issue 1 Pages 66-87
    Published: December 30, 1933
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    With the coverglass culture method, a relation between the temperature and the growth of the fibroblast in vitro was investigated. The growth was measured by tracing the surface increase.
    1) The growth of the tissue, which had been kept at 39° for one day after the preparation, was not a rectilinear function of the temperature between 25° and 43°, the maximum of the growth being at 39° and the minimum at 25°
    The growth between 25° and 39° could be approximately expressed with 2 exponential lines corresponding much more to VAN'T HOFF-ARRHENiUS's formula than to VAN'T HOFF's, with the point of inter-section lying at 30°.
    2) With culture tissue, which had been kept at 39° for 5 hours after the preparation the temperature influence an the growth was found to be not seriously different from the result in the former Gase. The temperature coeflicient Q10, was generally much larger than that of VAN'T HOFF's law, especially extraordinarily large between 25° and 27°. So also was the value of μ of VAN'T HOFF-ARRHENIUS.
    3) The growth of the tissue under alternating temperatures, but essentially under the saure temperature, that is, the growth of the tissue, which, after having been incubated at 39° for 5 hours after the preparation, was kept at a higher temperature an the first day and at a lower temperature an the second day, or vice versa, showed no essential differente between 30° and 39°. But there was a distinct differente in the Gase of 25° and 30°. The tissue which was kept first at 25° and then at 30° showed a smaller growth in comparision with that which was kept first at 30° and then at 25°.
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  • Isamu Stow
    1933 Volume 5 Issue 1 Pages 88-108_2
    Published: December 30, 1933
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    1) The relative reduction power and the hydrogen-ion concentration of the embryosac-like giant polten grain in Hyacinthaus orientalis were determined by means of.the indicator method.
    2) The reduction power of the cytoplasm of the embryosac-like giant pollen grain is larger than that of the normal pollen grain, both in artificially germinated and in non-germinated conditions.
    3) The reduction power of the cytoplasm of the embryosac-like giant pollen grain decreases after being influenced by the pollen tube.
    4) The Pollen tubes of another garden variety seldom grow in chemotropism-like manner towards the embryosac-like giant polten grain. In such a Gase, the polten tube usually entwines around the embryosac-like giant Pollen grain and sticks tightly.
    5) In one Gase, a sperm nucleus was just getting into the embryosac-like giant pollen grain out of the tip of a pollen tube. In another Gase, the P-nucleus was already divided into 16 nuclei, which seems to be caused as the result of a sperm nucleus having already fused with the P-nucleus in the embryosac-like giant pollen grain, though no exact evidence was found.
    6) From the results of the present investigations, the writer will conclude that the embryosac-like giant pollen grain possesses female tendencies to some degree, not only in general aspects of the development and morphologicaI structure, but also in some of the physico-chemical characters of the cytoplasm and the physiological functions.
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  • I. Chromosome number and morphology
    Ladley Husted
    1933 Volume 5 Issue 1 Pages 109-117
    Published: December 30, 1933
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    1. The somatic chromosomes of what is probably the “Rasteiro peanut” of Chevalier and of ten previously unpublished varieties and lines of A. hypogaea are forty in number.
    2. In all forms examined one pair of chromosomes is conspicuously smaller than any of the others of the complement. All the chromosomes possess median primary constrictions. Secondary constrictions are present. There is an indication that the chromosomes of a complement may be separated into classes containing from one to several chromosomes which appear identical in size.
    3. The Small chromosomes vary in length from 0.8 to 1.3 microns, the next in size from 1.2 to 1.7 microns, and the largest from 1.9 to 2.7 microns, depending upon the fixative and stain used.
    4. The haploid chromosome number of one bunch and two run-ner varieties of A. hypogaea is twenty. Irregular chromosome association has been observed. Secondary association is present.
    5. The bunch type and runner type peanuts investigated present the Same chromosome picture. It is concluded that as yet there is no cytological evidence to support Waldron's hypothesis of dual origin.
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  • G. W. Beadle
    1933 Volume 5 Issue 1 Pages 118-121
    Published: December 30, 1933
    Released: March 19, 2009
    JOURNAL FREE ACCESS
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  • J. Kruszynski
    1933 Volume 5 Issue 1 Pages 122-127
    Published: December 30, 1933
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    1. L'élimination du nucléole dans le protoplasma tout en étant quelquefois une expression de l'échange de matière entre le noyau et le protoplasma, est souvent produite artificiellement par la section de la pièce.
    2. Dans les cellules fixées, le nucléole a une consistance plus dense que la substance nucléaire qui l'entoure.
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  • Diploid and Tetraploid Avena
    C. D. Darlington
    1933 Volume 5 Issue 1 Pages 128-134
    Published: December 30, 1933
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    The quadrivalents formed by an autotetraploid Avena are of all the ten possible types. The equilibrium positions of their chiasmata are influenced by the spindle-attachment repulsions of chromosomes not taking part in them. The axial orientation of two members of a quadrivalent can be suppressed by that of the other two owing to the rigidity of the chromatids at an interstitial chiasma between the first two. These observations bear out the mechanical principles inferred from simpler configurations.
    I am indebted to Professor Kihara for kindly providing me with the facilities for undertaking this study in his department at the Biological Institute, Kyoto Imperial University.
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  • M. J. D. White
    1933 Volume 5 Issue 1 Pages 135-139
    Published: December 30, 1933
    Released: March 19, 2009
    JOURNAL FREE ACCESS
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  • K. Yasui
    1933 Volume 5 Issue 1 Pages 140-145
    Published: December 30, 1933
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    Ethyl aleohol fixation of smear materials for the study of general morphology of ehromosomes has been tested and found quite suitable for staining with various dyes, and especially suitable for FEULGEN's nucleal method.
    The writer's thanks are due to Einer. Prof. K. Fu ii for his suggestion and valuable advice. The expence for carrying out this study was partly defrayed out of a grant from the HATTORi Hokôkai, to which the writer wishes to express her best thanks.
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  • V. On the occurrence of an unexpected diploid in the progeny of pentaploid Avena hybrids
    Ichizo Nishiyama
    1933 Volume 5 Issue 1 Pages 146-148
    Published: December 30, 1933
    Released: March 19, 2009
    JOURNAL FREE ACCESS
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  • Wm. Bryden
    1933 Volume 5 Issue 1 Pages 149-153
    Published: December 30, 1933
    Released: March 19, 2009
    JOURNAL FREE ACCESS
    1. The chromosome number of the pig-Large White Yorkshire -has been studied and evidence points to the diploid number being 38.
    2. The meiotic stages have been studied and some observations have been made an the prophase, metaphase and anaphase stages.
    3. It appears that the haploid number is 19 and that the sex chromosomes may exhibit irregular behaviour.
    4. The evidence points to the sex-chromosomes being of the XY type.
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