. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 418 ELMER L. SHAFFER. which are similar to those found in the protobroque and deuto- broque (preleptotene) nuclei. In the later stages these bodies become closely associated (Text-fig. 3, Figs. 81, 84) and persist as definite chromatin nucleoli. A true plasmosome is also present in these stages which becomes vacuolated and grows in size with the age of the oocyte (pi., Figs. 44, 46). In the older germinal $, r n. TEXT-FIG. 3. Oocyte of post-synaptic period, showing mitochondria arranged in perinuclear zone, and two chromatin
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. 418 ELMER L. SHAFFER. which are similar to those found in the protobroque and deuto- broque (preleptotene) nuclei. In the later stages these bodies become closely associated (Text-fig. 3, Figs. 81, 84) and persist as definite chromatin nucleoli. A true plasmosome is also present in these stages which becomes vacuolated and grows in size with the age of the oocyte (pi., Figs. 44, 46). In the older germinal $, r n. TEXT-FIG. 3. Oocyte of post-synaptic period, showing mitochondria arranged in perinuclear zone, and two chromatin nucleoli () and a plasmosome (pi.). vesicles, the two chromatin nucleoli may persist (Fig. 87), but more commonly a single large chromatin nucleolus is found together with six to eight smaller nucleoli (Fig. 46). It is difficult to say whether the two chromatin nucleoli really represent persisting sex-chromosomes and are therefore homol- ogous to the chromosome nucleoli of the spermatocytes. There is some evidence that this is the case. The disappearance of the definite nucleoli during the synaptic stages (leptotene and pachy- tene) leads me to believe that they are resolved into chromatic threads which go through a synaptic process similar to the autosome threads. The fact that there are ten pachytene threads in the bouquet stage indicates that all the chromosomes are in synapsis. The reappearance of the two chromatin nucleoli in the strepsistene stages are perhaps brought about by a re-con- densation of the synaptic threads representing the sex pair resulting in the formation of the two compact chromatin 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, Fr
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