A Study of the Spermatogenesis of Twenty-two Species of the Membracidę, Jassidę, Cercopidę and Fulgoridę ...

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1907 - Entomology, Structural - 512 pages
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Page 502 - Hvittata Pceciloptera bivittata very closely resembles the last described species, even to the number and relative sizes of its chromosomes (Figs. 305-313). It has two plasmosomes in the growth period, and one or both of these persist in a most remarkable fashion even to the anaphase of the second spermatocyte division (Fig. 312). The size of the chromosomes and cells is greater than in Amphiscepa bivittata. THEORETICAL CONSIDERATIONS Individuality of the Chromosomes The theory of the individuality...
Page 509 - 06 — Die Spermatogenese von Pyrrhocoris apterus. Zool. Jahrb., xxiii, p. 269. HENKING, H., '90a — Untersuchungen iiber die ersten Entwicklungsvorgange in den Eiern der Insekten. II Ueber Spermatogenese und deren Beziehung zur Eientwicklung bei Pyrrhocoris apterus.
Page 512 - 95 — Spermatogenesis of Caloptenus femur-rubrum and Cicada tibicens. Bull. Mus. Comp. Zool., Harvard, xxvii, p. 3. "96 — Further Studies on the Spermatogenesis of Caloptenus femurrubrum. Bull. Mus. Comp. Zool., Harvard, xxix, p.
Page 510 - Menidia notata with Especial Reference to Behavior of Maternal and Paternal Chromosomes. Am. Journ. Anat., 3: 29-64. Montgomery, Jr., TH 1906. Chromosomes in the Spermatogenesis of the Hemiptera heteroptera. Trans. Am. Phil. Soc., N. 8., 21: 97-173. 1908. On the Morphological Difference of the Chromosomes of Ascarig megalocephala.
Page 509 - 90 — Vergleich der Ei- und Samenbildung bei Nematoden. Arch. f. Mikr. Anat., xxxvi, p.
Page 508 - ... arcuata to the metaphase of the second spermatocyte division, and in Enchenopa binotata, from the spermatogonial plate to the telophase of the second spermatocyte division. 11 In all 22 species, there is a dimorphism of the spermatozoa, which probably corresponds to the natural dimorphism of sex. 12 Two species of Fulgoridae in which the female somatic number of chromosomes is 28, while the spermatogonial number is 27, furnish further proof for the theory of sex determination advanced by McClung,...
Page 507 - In the spermatids of 19 species; that is, all except three of the Membracidae, there is a chromatin nucleolus in all of the spermatids entirely independent of the odd chromosome. In seven of these species, the odd chromosome is present also in half of the spermatids, in others there is no indication of it. In the three Membracidae without the chromatin nucleolus, Entilia sinuata, Vanduzea arcuata, and Campylenchia curvata, the odd chromosome is present in half of the spermatids. 4 In the genus Ceresa,...
Page 510 - ... Study of the Spermatogenesis of Coptocycla aurichalcea and Coptocycla guttata, with especial reference to the Problem of Sex Determination. Jour. Exp. Zool., iii, p. 583. OTTE, H., '06 — Samenreifung und Samenbildung von Locusta viridissima. Zool. Anz., xxx, p. 529. PAULMIER, FC, '98 — Chromatin Reduction in Hemiptera. Anat. Anz., xiv, p. 514. PAULMIER, FC, '99 — Spermatogenesis of Anasa tristis. Jour. Morph., xv, supplement, p. 223. PLATNER, G., '86 — Die Karyokinese bei den Lepidoptera...
Page 497 - II instead of 12, so material was fixed in Gilson and kept to be studied at a convenient time. The material was obtained from two distinct localities, but not kept separate. The sections showed follicles with II chromosomes and a few with 12. Whether this difference corresponds with the difference in locality it is unfortunately not possible to say. Another peculiarity is that the form with 12 chromosomes does not resemble, in some of its stages, the form with 12 chromosomes described by Stevens....
Page 492 - Fig. 127 shows an occasional first spermatocyte with 11 chromosomes, implying a delay in the fusion of one pair. Here we find the chromatin nucleolus in all the spermatids (Fig. 136). J as si dee The testes of the Jassidae are pale yellow in color, and therefore very easy to dissect out. The follicles are about three times as long as broad; this makes it easier to trace the development from stage to stage than in the Membracidae. My material includes six species, four of them caught at Cold Spring...

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