CYTOLOGIA
Online ISSN : 1348-7019
Print ISSN : 0011-4545
Volume 7, Issue 1-2
Displaying 1-22 of 22 articles from this issue
  • I. Polyploidy and the origin of new species
    Henry Wilhelm Jensen
    1936 Volume 7 Issue 1-2 Pages 1-22_1
    Published: May 31, 1936
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
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  • II. The origin and behavior of the so-called sex-chromosomes in Rumex
    Henry Wilhelm Jensen
    1936 Volume 7 Issue 1-2 Pages 23-34_2
    Published: May 31, 1936
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    1. A study of the meiotie spireme in Rheum and Rumex reveals that the spireme is essentially continuous throughout its tangible history, through diakinesis, and that the meiotic chromosomes originate by a longitudinal Splitting of the spireme out of which the haploid number of chromosomes becomes segmented. Pairing does not take place in these genera because it cannot.
    2. Because the above conelusion necessitates a fusion of maternally and paternally contributed chromosomes before meiosis, thus destroying the individuality of the chromosomes, sex-chromosomes cannot exist in Rumex.
    3. From another angle, the so-called sex-chromosomes in R. Acetosa and R. acetosella are regarded as having little to do with the determination of sex, because……,
    4. The described apparatus does not exhibit a uniform behavior, but rather one of irregularity.
    5. The tripartite chromosomes reveal themselves to be essentially tetrapartite; a string of four elements the inner of which frequently fuse and behave as one entity.
    6. Tripartite chromosomes also exist and perform an unequal distribution of the meiotic chromosomes in R. pallidus, but this species is hermaphroditic.
    7. The dioecious species in question exhibit various cytological phenomena which indicate that they are of hybrid origin.
    8. The meiotic phenomena in the dioecious species are duplicated to a large extent in the hybrid R. crispus×obtusifolius.
    9. The so-called sex-chromosomes in Rumex are therefore nothing more than an abnormality resulting from previous hybridization of the species.
    10. A peculiar cytological condition present in Rheum rhaponticum is used to demonstrate that a condition ascribed to sexdetermination in some unisexual organisms may also exist in hermaphrodetic species and thereby annul the logical existence of such sex-chromosomes.
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  • J. Polívková
    1936 Volume 7 Issue 1-2 Pages 35-53
    Published: May 31, 1936
    Released on J-STAGE: March 19, 2009
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    The Development of the Typical Forms of Gemini: The Origin of Crossing-over
    Each of the eight gemini of Clematis Jackmanii reaches during the phases of chromosome conjugation a typical form. Text-fig. I-1.
    The typical forms of gemini are determined by the position and number of the first and second torsions.
    Two chromosomes of the same pair lie in meiosis associated side by side by the reductional split, before they split into four chromatids (two and two daughter-chromatids).
    The first torsion appears after the moment that the two chromosomes associated side by side split into two and two daughter-chromatids. This torsion is determined by the torsion at 180° round the axis of each of the two chromosomes of the same pair. This torsion is the same in meiosis as it is in mitosis. Models III-1.
    The second torsion occurs before the moment that the two chromosomes associated side by side in a pair split into two and two daughter-chromatids: the two chromosomes turn one over the other. Models III-5.
    At early diplotene the daughter-chromatids separate one from the other by their equational split until they reach the vertical position one to the other at the point of the first torsion: at this point an one side of the reductional split lie two daughter chromatids vertically one an the other, an the other side of the reductional split lie the other two daughter-chromatids in the saure way; before and behind this point the two dissimilar-chromatids remain associated side by side by the reductional split. This is the structure s.a. Text-fig. II-4: Models III-3, 14.
    If there is also the second torsion in this geminus, when at diplotene the daughter-chromatids separate one from the other, then at its point the two dissimilar-chromatids associated side by side by the reductional split are turned over the other two dissimilar chromatids. (This is the structure s.b.) Models III-6, 10, 15-19, 21.
    The composition of each of the eight gemini of the four ehromatids and the way of the intermingling of these four chromatids is best seen at highest diplotene. Models I.
    The daughter-gemini separate at first anaphases one from the other by the reductional split; they then have a form similar to the forms of gemini in diakinesis. Text-fig. I-2, III.
    If there are interchanges of corresponding Segments between the chromatids of a geminus during the phases of chromosome conjugation, these interchanges are accomplished before the geminus is at diakinesis.
    The segmental composition of the four chromosomes resulting from the chromosome conjugation with only the first torsion remain unchanged. This corresponds to the gemini f, g, h. Text-fig. III-1-3; Models III-4.
    The chromosomes resulting from the chromosome conjugation with the first and the second torsion have interchanged corresponding segments. This corresponds to the gemini a, b, c, d, e. Text-fig. III-4-8; Models III-9, 13.
    The second torsion determines the origin of crossing-over: the crossing-over takes place between two dissimilar chromatids at the point given by the second torsion; the interchange of corresponding segments between two dissimilar chromatids is accomplished by the breakage and reunion before diakinesis. Text-fig. II-5.
    If the second torsion is not fully at 180°, the crossing-over takes place between two dissimilar-chromatids: Each of the four chromosomes resulting from this chromosome conjugation has a different segmental composition; two have interchanged corresponding segments; the other two remain unehanged, each of them having the saure segmental composition as one of the two chromosomes of the same pair before their conjugation. This corresponds to the geminus b. Models III-10-13.
    If the second torsion is at 180°, the erossing-over takes place in both the two dissimilar chromatids. There is a difference in the position of these two points
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  • 1. Bildung von Zellen und Blutinseln aus Dotterkugeln beim Hühnerembryo
    O. B. Lepeschinskaja
    1936 Volume 7 Issue 1-2 Pages 54-81
    Published: May 31, 1936
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    1. Die phylogenetische Entwicklung der Zelle führt vom lebenden Protoplasma über Zwischenformen (Protoplasmaklümpchen (“Moneren”), die Pseudopodien bilden und einziehen). Im Organismus gibt es stets lebende, nicht zu Zellen geformte protoplasmatische Gebilde, und damit ist auch die Möglichkeit einer Transformation dieser Massen zu zelligen Gebilden nicht ausgeschlossen.
    2. Die Dotterkugeln haben viel Gemeinsames mit den Übergangsformen zwischen protoplasmatischen Massen und Zellen und bilden das günstigste Objekt für das Studium der Entstehung der Zellen aus protoplasmatischen Massen.
    3. Kugeln, die aus der Dottermasse in die Subembryonale Höhle herausgefallen sind, weisen auf verschiedenen Entwicklungsstadien der Embryonen einen verschiedenen Bau des Kerns auf: “protoplasmatische Kerne”, “Kern mit dem Anfangsstadium der Lininnetzbildung”, völlig ausgebildeter Kern, Kerne auf verschiedenen Stadien der karyokinetischen Teilung. Indem sich die “Zellkugeln” einander nähern, bilden sie das entodermale Blatt.
    4. In einer Gewebekultur unterscheiden sich die weißen Dotterkugeln von den gelben durch ihr dünnflüssiges Protoplasma und ihre Befähigung zu amöboiden Bewegungen; ihre Granula befinden sich in BROWN'scher Bewegung, die zu einer polarisierten wird und auf diesem Wege zur Entstehung des Kerns führt. Der Entstehungsprozeß des Kerns führt über eine Reihe aufeinanderfolgender-qualitativ verschiedener Stadien, nämlich: Kondensierung der Körnchen, Bildung eines homogenen rundlichen Körpers (“Lininnetzgerüst”), Eintritt der Granula in das “Linnetzgerüst” und Umwandlung des mit Eosin färbbaren homogenen Körpers zu einem (Linin)-Netz, Austritt der großen Körner aus dem neugebildeten granulierten Kern nach außen, Lagerung dieser Körner um den Kern mit der in ihm verbliebenen feinen Granulation, schließlich die karyokinetische Teilung der neuentstandenen Zellen. Am zweiten Tag entsteht aus diesen sich teilenden Zellen ein Syncytium.
    5. Aus den Dotterkugeln, die in den Hohlraum zwischen den Keimblättern gelangten, entstehen Blutinseln. Sowohl auf histologischen Präparaten von in Entwicklung begriffenen Embryonen, wie in Gewebekulturen können die verschiedenen Stadien der Entstehung von Blutinseln verfolgt werden.
    6. Auf Grund des vorhandenen experimentellen Materials, drängt sich der Gedanke auf, daß VIRCHOW Unrecht hatte, als er behauptete, daß Zellen nur durch Teilung aus Zellen entstünden, daß im Organismus keine Neubildung von Zellen möglich sei, und daß die Zellen das letzte zur Lebenstätigkeit befähigte morphologische Element seien. Alle unser Beobachtungen sprechen dafür, daß die Dotterkugeln, die keine Zellen sind, zur Lebenstätigkeit, zu formativen Prozessen und selbst zur Umwandlung in Zellen befähigt sind. Anscheinend vermehren sich die Zellen nicht nur, wie es VIRCHOW behauptete, durch Teilung, sondern auch durch Transformation aus nichtzelligen protoplasmatischen Massen.
    Wir betrachten unsere Arbeit als unbeendet und halten es für notwendig, sie mit Hilfe des Ultropaks und des Mikrokinematographen einer genauen Nachprüfung zu unterziehen.
    Ich möchte auch an dieser Stelle dem Direktor des Instituts B.P. TOKIN meinen herzlichsten Dank für seine strenge und ernst Kritik meiner Arbeit bei deren Ausführung aussprechen. Zu großem Dank bin ich ferner Herrn Prof. STCHEGOLEFF für seine wertvolle Ratschläge und seine Hilfe beim Auffinden der einschlägigen Literatur, sowie meinen Mitarbeitern AGAROWA und SCHOLOCHOFF verpflichtet.
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  • XI. Dasyurus and Sarcophilus
    P. C. Koller
    1936 Volume 7 Issue 1-2 Pages 82-103
    Published: May 31, 1936
    Released on J-STAGE: March 19, 2009
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    1. Dasyurus and Sarcophilus have six pairs of autosome chromosomes. In Sarcophilus they show slight variation in length; in Dasyurus this is greater. The loci of attachment constrictions are median, submedian or subterminal.
    2. The ehromosomes exhibit somatic pairing at mitotic metaphase.
    3. The contraction of prophase chromosomes at mitosis is less in Sarcophilus than in Dasyurus, and the time required to arrive at the metaphase stage is longer.
    4. At meiotic prophase the chromosomes contain well defined chromomeres. The number of varying sizes of chromomeres is the same in homologous chromosomes.
    5. The zygotene and pachytene stages are very long. The pairing of homologous ehromosomes begins in one of the terminal regions, and never more than two separate segments of the same chromosome are involved.
    6. At the end of pachytene a sudden change takes place in the first spermatocyte; the chromosomes loose their staining capacity and the volume of nuclei and Gell inereases. It is suggested that this stage is equivalent to the resting stage in that the delayed splitting of chromosomes occurs.
    7. In Dasyurus there is a high chiasma interference with lower chiasma frequency than in Sarcophilus.
    8. The relationship between the length of chromosomes and the chiasma frequency is disproportionate in Dasyurus, but is independent in Sarcophilus.
    9. The different types of pachytene interlocking are described. One Gase is illustrated where interlocking leads to segmental interchange.
    10. Chiasma frequency in multinucleate spermatocytes shows slight variation within the saure cell, which variation must be genetic.
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  • J. Gordon Carlson
    1936 Volume 7 Issue 1-2 Pages 104-117
    Published: May 31, 1936
    Released on J-STAGE: March 19, 2009
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    1. The Feulgen reaction maintains its specificity after each of the nine different fixatives used; of the cell components it stains the chromatin only.
    2. The intensity of the staining reaction of the root tip cuticle by the Feulgen technique usually varies with the fixation as does that of the chromatin.
    3. For each of the other stains employed (Heidenhain's iron alum-hematoxylin, crystal violet-iodine, and safranin-iodine) the stainabilities of the different ceil structures are conditioned directly by the fixative.
    4. Crystal violet-iodine and safranin-iodine exhibit no consistent differences in their selectivity for the various cell organs after any of the fixatives.
    5. After certain fixatives the hydrochloric acid treatment used for the partial hydrolysis of the thymonucleic acid for the Feulgen reaction (N HCl at 60°C. for 20 minutes) affects the relative staining capacities of plastin and chromatin, when the iron alum-hematoxylin, crystal violet-iodine, and safranin-iodine stains are used.
    6. Only the Bouin and Navashin-fixed material is affected by hydrochloric acid treatment in the reaction to iron alum-hematoxylin: in both the chromatin loses some of its staining capacity; in the latter the stainability of the nucleoli is increased as well.
    7. The effects of treatment with hydrochloric acid an the staining reactions of crystal violet-iodine and safranin-iodine is quite pronounced for several fixatives: chromatin stainability is increased after modified Erlicki, decreased after Navashin and copper bichromate, and lost after Bouin fixation; nucleolar stainability is acquired after copper-chrome-propionate, increased after Navashin, copper bichromate, and chromic sulfate-formaldehyde, decreased after modified Erlicki, and decreased or lost after nickel-chrome-propionate fixation.
    8. Copper-containing fixatives that render the nucleoli stainable with crystal violet-iodine and safranin-iodine cause the nucleolar peripheries to stain darker than the Centers, while after hydrochloric acid treatment this reaction is reversed, the centers staining darker than the peripheries.
    9. In some preparations mitotic nucleoli differ from intermitotic nucleoli in their reactions to stains, which would seem to indicate that the nucleolus undergoes some chemical or physical change at the initiation of mitosis.
    10. Evidence is presented in support of the view that plastin, as well as chromatin, occurs in the form of granules in the reticulum of the intermitotic cell.
    11. Nucleoli, which are mordanted by copper-containing fixatives only if the pH is above 4.0, are but little affected in regard to their stainability by subsequent treatment with hydrochloric acid of a much lower pH.
    12. Mitochondria, which are usually dissoived out by the more acid fixatives, are not affected by treatment with normal hydrochloric acid after fixation.
    I want to express my appreciation to Dr. Conway Zirkle for suggesting this problem, as well as for his help and advice throughout the course of the investigation.
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  • Eremurus spectabilis
    Margaret Upcott
    1936 Volume 7 Issue 1-2 Pages 118-130
    Published: May 31, 1936
    Released on J-STAGE: March 19, 2009
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    1. The chromosome complement of Eremurus spectabilis consists of 7 pairs of chromosomes, five of which are Jong and two short.
    2. Somatic pairing occurs in the root-tip divisions and is more frequent among the short chromosomes.
    3. There is no direct proportionality between chiasma frequency and length.
    4. The rate of terminalisation is greater in the skort bivalents than in the long.
    5. The nucleolus is still attached to the end of one of the long bivalents at diplotene, generally only by one arm. The connection is often drawn out into a fine thread, suggesting the presence of a surface charge an the nucleolus similar to that an the chromosomes. The terminalisation of the attached bivalent is reduced, possibly owing to the proximity of the nucleolus.
    6. True and false interlocking was found at the three stages examined, and one Gase of double interlocking, a configuration only possible if crossing-over had occurred.
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  • Herbert Parkes Riley
    1936 Volume 7 Issue 1-2 Pages 131-142
    Published: May 31, 1936
    Released on J-STAGE: March 19, 2009
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    1. Meiotic chromosomes of Tradescantia gigantea, after subjection to X-rays, tend to become contracted and clumped. Chromosomes which were irradiated during a premeiotic mitosis show extreme fragmentation, segmental interchange and, in mang Gases, a failure of pairing at the subsequent meiotic divisions.
    2. Irradiation during the microspore metaphase or anaphase produces fragmentation, and the effect is immediate. Treatment during prophase also produces unbalanced fragments, translocations and occasional interchange rings; also an occasional balanced configuration.
    3. When cells in the resting stage before the microspore division are treated with X-rays, the subsequent metaphases and anaphases show balanced abnormalities only. The fact that chromosomes irradiated at prophase or later stages show chiefly unbalanced fragments, while those which were in the resting stage when subjected to X-rays show only balanced abnormalities, is evidence that the chromosomes do not split until late in the resting stage.
    4. No inhibition nor delay of division is found. Actively dividing cells are present continuously after irradiation in both meiosis and microspore divisions at the dosages used.
    5. Evidence is offered to show that attachment points do not arise de novo and that the contraction of the chromosomes between prophase and metaphase is not due to the action of the attachment points.
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  • H. P. Olmo
    1936 Volume 7 Issue 1-2 Pages 143-159
    Published: May 31, 1936
    Released on J-STAGE: March 19, 2009
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    The meiotic behavior of the univalent chromosome in monosomic (2n-1) types of Nicotiana tabacum var. purpurea is described.
    Evidence is presented indicating that abnormal behavior of the univalent chromosome may provide the opportunity for new chromosomal rearragements.
    Various types of aberrant plants appearing in the progenies of the monosomic types are described. These inelude trisomics, triploids, and others having various structural rearrangements of the chromosomes.
    Monosomism creates a condition of genetical unbalance that may serve as the source of numerical or structural ehromosomal recombinations.
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  • Haig Dermen
    1936 Volume 7 Issue 1-2 Pages 160-175
    Published: May 31, 1936
    Released on J-STAGE: March 19, 2009
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    The species of Verbena studied here fall into two cytological classes, one wich a basic number n=5 chromosomes, the other wich n=7. The chromosomes of the n=7 dass were approximately half to one sixth as large as those of the n=5 dass. This classification was found to correspond to taxonomical classification. The genus is divided taxonomically into two sections: Glandularia and Verbenaca. The species of the latter seetion are further divided into two series: Pachystachyae and Leptostachyae. All the species with n=5 and n=15 chromosomes belong to the Glandularia section. The polyploid forms of the n=7 dass and V hispida, a diploid form, are classified under Pachystachyae, and the other diploid species under Leptostachyae of the Verbenaca section.
    Hybridization was attempted between all the species under investigation. Hybrids were obtained, first between the species with n=5 chromosomes and between the species wich n=5 and n=15 chromosomes; secondly, between any two species wich n=7 chromosomes and between the species with n=7 and n=14 chromosomes, but not between n=7 and n=21, nor between n=14 and n=21 chromosomal species. Hybrids were not obtained from crossing species of the two classes referred to above with a basic difference of n=5 and n=7 chromosomes. In all Gases the hybrid plants were intermediate in general characteristics between their parent plants.
    A diploid and a hexaploid species in Glandularia section were crossed resulting in a tetraploid hybrid which was highly sterile. In the section Verbenaca successful Grosses were made between a diploid and two tetraploid species. In one Gase (V. hispida×V. bonariensis) the hybrid plants were triploid while in another (V. hispida×V. litoralis) only pentaploid hybrids were obtained, a total of five plants, two of which resembled closely the female parent and three the male parent.
    Hybrids were obtained between V hybrida and V. erinoides each with n=5 chromosomes. The chromosomes in the former are somewhat Tonger than in the latter. These differences could be observed both in root-tip sections and meiotic preparations.
    Suggestions are presented as to the mode of origin of tetraploid and hexaploid species.
    Two types of Gell size differences are presented, in one of which increase in volume appears to be physical, in the Sense Navaschin has described, and the other genetical.
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  • G. Gazet du Chatelier
    1936 Volume 7 Issue 1-2 Pages 176-183
    Published: May 31, 1936
    Released on J-STAGE: March 19, 2009
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    1° Le Sterculia platanifolia fournit des boutons floraux uniformement hermaphrodites. Il se produit, ultérieurement, parmi ces derniers, une orientation sexuelle spéciale consistant d'une part, en l'avortement de certains ovaires, d'autre part, en la non-déhiscence des étamines des fleurs demeurées hermaphrodites.
    2° L'étude cytologique des cellules-mères du pollen et du sac embryonnaire, nous met en présence de cas de non-disjonction réductionnelle et équationnelle de chromosomes. Cette anomalie permet de concevoir l'existence de mutants.
    3° L'étude des ovules abortifs montre indiscutablement que l'avortement de certains ovaires ne peut pas être rapporté à une cause cytologique. Seule, une explication physiologique parait rationnelle; mais il ne semble pas qu'il faille la rechercher dans une réduction du nombre des vaisseaux ligneux qui se rendent aux carpelles.
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  • Diploid and tetraploid Culex pipiens
    A. A. Moffett
    1936 Volume 7 Issue 1-2 Pages 184-197
    Published: May 31, 1936
    Released on J-STAGE: March 19, 2009
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    (1). The chromosome number in Culex pipiens is 2n=6. Tetraploid cells have been observed in both mitotic and meiotic divisions.
    (2). In somatic divisions the homologous chromosomes show strong association throughout all stages of division, being in pairs in the diploid and in fours in the tetraploid. Somatic pairing in relation to the anomalous type of meiosis in the male Drosophila is discussed.
    (3). At meiosis in tetraploid cells, quadrivalents, bivalents and univalents occur, the number of multivalents being low. The failure of complete pairing may be due to three causes:
    (a) Low number of pairing blocks per chromosome.
    (b) Failure of chiasma formation in parts of chromosomes which have paired over a short distance.
    (c) Mechanical interference preventing chromosomes pairing at zygotene.
    (4). The chiasma frequency at Metaphase I differs in different individuals from 1.06 to 1.64 per bivalent. These differences are considered to be due to the action of different genotypes an chromosome pairing at meiosis.
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  • Die Einwirkung der Plasmolyse auf die Mitose bei den Staubfadenhaarzellen von Tradescantia reflexa
    Bungo Wada
    1936 Volume 7 Issue 1-2 Pages 198-212_2
    Published: May 31, 1936
    Released on J-STAGE: March 19, 2009
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    1. Die Einwirkung der Plasmolyse auf die Mitose der jungen Staubfadenhaarzellen von Tradescantia reflexa wurde im lebenden Zustande der Zelle untersucht, wobei die Beziehungen zwischen den Chromosomen, den Chromonemata und der Struktur des Ruhekernes experimentell festgestellt wurden.
    2. Bei den plasmolysierten mitotischen Figuren treten die Chromonemata einzelner Chromosomen durch den Verlust ihres Quellungswassers deutlich hervor. Die Spiraiwindungen der Chromonemata fasern sich ungeachtet des Schlusses der Karyokinese bei der nachherigen Behandlung mit hypotonischer Lösung auf, und die so gelösten Chromonemata reduzieren sich zu einem Ruhekerne. Daher entsteht aus den Chromosomen in der Meta und Anaphase ein Syndiploidkern mit unvollkommener oder ohne Scheidewand.
    3. Durch die Plasmolyse der Mitose in der Anaphase erweisen sich. Chromosomen in der Chromosomenbrücke nach dem Verlust ihres Quellungswassers im ausgedehnten Zustande als parallel liegende und im losgelösten Zustande als vielverschlungene Chromonema-Fäden.
    4. Bei der Plasmolyse der Mitose zeigt das Atraktoplasma fast keine Änderung, jedoch weist der Phragmoplast dabei deutlich Entquellung auf und verschwindet späterhin im Zytoplasma. Daher entsteht eine zweikernige Zelle durch die Plasmoly, se der Mitose in der Telophase.
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  • Jakob Ellenhorn
    1936 Volume 7 Issue 1-2 Pages 213-218
    Published: May 31, 1936
    Released on J-STAGE: March 19, 2009
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  • C. W. Metz
    1936 Volume 7 Issue 1-2 Pages 219-231
    Published: May 31, 1936
    Released on J-STAGE: March 19, 2009
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  • Paul L. Risley
    1936 Volume 7 Issue 1-2 Pages 232-241
    Published: May 31, 1936
    Released on J-STAGE: March 19, 2009
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  • Podophyllum versipelle
    C. D. Darlington
    1936 Volume 7 Issue 1-2 Pages 242-247
    Published: May 31, 1936
    Released on J-STAGE: March 19, 2009
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    1. Bivalents may fall to orientate themselves an the spindle at meiosis in Podophyllum versipelle; their centromeres then fail to show the special repulsion, which acts only in an axial direction.
    2. At interphase the major spirals of the first division appear as relic spirals, which are gradually lost as the chromosomes spiralise for the second division. The degree of spiralisation varies in different nuclei.
    3. Asymmetrical movement at the pollen grain anaphase results from stretching of the spindle when one group of chromosomes is obstructed by the wall. An acentric “chromatid-chromosome” was found to lag without dividing. The centromere therefore seems to control division in the resting stage as well as separation at anaphase.
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  • Relational coiling of chromatids at mitosis
    C. D. Darlington
    1936 Volume 7 Issue 1-2 Pages 248-255
    Published: May 31, 1936
    Released on J-STAGE: March 19, 2009
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    1. The daughter chromatids are optionally coiled round one another at the metaphase of mitosis. The direction of coiling is usually consistent in each arm of all chromosomes in Fritillaria and constant for the identifiable M chromosomes. In Nomocharis however the direction is sometimes inconsistent in particular arms.
    2. Chromatid coiling at metaphase seems to be developed during prophase chiefly as a result of a strain imposed an the chromatids by spiralisation but subject also to other conditions that have not yet been ascertained.
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  • H. Pfeiffer
    1936 Volume 7 Issue 1-2 Pages 256-263
    Published: May 31, 1936
    Released on J-STAGE: March 19, 2009
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    Nachdem verschiedene Vor versuche zu keiner überzeugenden Entscheidung über eine Beeinflussung der Reißfestigkeit (Kohäsion) des Plasmalemma nackter Protoplasten während der Plasmorrhyse geführt haben, wird in den Hauptversuchen ein geeignetes Versuchsprinzip in dem eben zur Ruptur des Objekts (Plasmoptyse) führenden Concentrationsgrade langsam permeierender Substanzen mitgeteilt. Außer einer ausführlichen Darstellung der Versuchsanstellung werden die grundlegenden Resultate zusammengefaßt, nach denen erhöhte Plasmorrhysegrade mit gesteigerter Reißfestigkeit (Kohäsion) verknüpft sind, wobei der kohäsionssteigernde Einfluß nach der Natur des benutzten Plasmorrhytikums variiert und im ganzen der quellungsbeeinflussenden Wirkung der beteiligten Salzionen symbath geht. Durch Untersuchung der Te m peraturabhängigkeit wird jener Schluß weiter gestützt, doch scheinen Viscosität sverschiebungen und vielleicht koagulative Einflüsse gleichfalls mitzuwirken. Anhangsweise wird die Veränderung der metabolen Deformierbarkeit im Zusammenhange mit steigenden Plasmorrhysestufen behandelt, und endlich wird die noch weiter zu verfolgende Frage einer Beeinflussung des Elastizität smoduls des Plasmalemma in Abhängigkeit vom Plasmorrhysegrade diskutiert.
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  • Ernst Küster
    1936 Volume 7 Issue 1-2 Pages 264-271
    Published: May 31, 1936
    Released on J-STAGE: March 19, 2009
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  • Sukeichi Fujii
    1936 Volume 7 Issue 1-2 Pages 272-275
    Published: May 31, 1936
    Released on J-STAGE: March 19, 2009
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  • I. Chromosome association in hybrids between Avena barbata POTT. and autotetraploids of A. strigosa SCHREB
    Ichizo Nishiyama
    1936 Volume 7 Issue 1-2 Pages 276-281
    Published: May 31, 1936
    Released on J-STAGE: March 19, 2009
    JOURNAL FREE ACCESS
    This paper deals with an analysis of chromosome pairing, especially associations between the A and B' genoms, in hybrids between Avena barbata (AAB'B') and autotetraploids (AAAA). In addition to 7 bivalents (from pairing between A and A), usually 5 bivalents and often 6 were formed between B' and the remaining A genom. In the extreme case all chromosomes entered into pairing relationship but more than 13 bivalents, inclusive of some multivalent associations, were not found. The mode of chromosome pairing is discussed.
    The writer wishes to express here his best thanks to Professor KIHARA and Dr. F. LILIENFELD for their valuable criticism and help in this work.
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