. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. THE SPERMATOGENESIS OF THE MYRIAPODS. 193 tocytes to that of the spermatogonium stands in a ratio of ten to one. Striking as this great increase in the size of the cells certainly is, it is not as remarkable as are the changes which occur in the cell in general and especially in the nucleus. Shortly after the formation of the nuclear membrane, the chromatin segments leave the tangled mass at one side of the nucleus (Fig. 5), and arrange themselves irregularly throughout the nuclear space (Fig. 6). At the same time they short
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. THE SPERMATOGENESIS OF THE MYRIAPODS. 193 tocytes to that of the spermatogonium stands in a ratio of ten to one. Striking as this great increase in the size of the cells certainly is, it is not as remarkable as are the changes which occur in the cell in general and especially in the nucleus. Shortly after the formation of the nuclear membrane, the chromatin segments leave the tangled mass at one side of the nucleus (Fig. 5), and arrange themselves irregularly throughout the nuclear space (Fig. 6). At the same time they shorten and thicken and, as the nucleus is now quite large, the individual elements may readily be distinguished and their number counted. In all favorable cases. FIG. 8. X I>44° dia. Pseudo-germinal vesicle stage of the spermatocyte of Sco- lopendra heros. Chromatin all aggregated in karyosphere which here plainly shows ex- cept at one point a spongy or reticular structure. This dense portion undoubtedly represents the accessory chromosome. Persisting spindle still visible. Centrosomes to be seen imbedded in the zone of archoplasm surrounding the nucleus. in which this count has been taken it has been found that there are seventeen chromosomes present (sixteen granular segments and the accessory chromosome), the number later found in the metaphase. At this time (Fig. 6) the cells resemble insect spermatocytes more closely than at any other stage. They are now in a condition apparently comparable in all particulars to that of the ordinary sperm cell in the "segmented spireme". 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 Ri
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