. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. SEXUAL PHASES IN AMERICAN OYSTER 423 By the middle of October, at the age of about three months, the shells of some individuals have become 20-25 mm. in length, and in these the gonads have already become distinctly bisexual (Figs. 2-6). A typical section through the genital canal at this age (Fig. 2) shows more or less numerous indifferent cells remaining along the inner border, interspersed with large ovocytes in which the coarse mitochondrial filaments of the so-called yolk nuclei are always con-. FIG. 4. Primary intersex
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. SEXUAL PHASES IN AMERICAN OYSTER 423 By the middle of October, at the age of about three months, the shells of some individuals have become 20-25 mm. in length, and in these the gonads have already become distinctly bisexual (Figs. 2-6). A typical section through the genital canal at this age (Fig. 2) shows more or less numerous indifferent cells remaining along the inner border, interspersed with large ovocytes in which the coarse mitochondrial filaments of the so-called yolk nuclei are always con-. FIG. 4. Primary intersexual gonad in an animal about four months of age, showing indifferent cells (I) and several large ovocytes (oc), with spermatocytes (spc I) and a single spermatid (spt) bordering the ciliated genital canal (gc). spicuous. Morphologically less well differentiated are the ovogonia and spermatogonia which resemble each other so closely that they cannot ordinarily be distinguished. Both types of cells then pass through similar synaptic phases accompanied by spiremes of coarse, densely-staining chromosomes (Figs. 2, 3, 9B, 9C) as they transform into ovocytes and primary spermatocytes respectively. The spermatogonia proliferate rapidly, leading to the formation of the numerous spermatocytes wrhich soon give the intersexual gonad. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Marine Biological Laboratory (Woods Hole, Mass. ); Marine Biological Laboratory (Woods Hole, Mass. ). Annual report 1907/08-1952; Lillie, Frank Rattray, 1870-1947; Moore, Carl Richard, 1892-; Redfield, Alfred Clarence, 1890-1983. Woods Hole, Mass. : Marine Biological Laboratory
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
