SPERMATOGENESIS IN PHILOSAMIA CYNTHIA
| Autor: | Pauline H. Dederer |
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| Rok vydání: | 1907 |
| Předmět: | |
| Zdroj: | The Biological Bulletin. 13:94-106 |
| ISSN: | 1939-8697 0006-3185 |
| DOI: | 10.2307/1535676 |
| Popis: | 1. The spermatogonia contain twenty-six chromosomes, of approximately the same size and shape.2. There is a definite spireme stage with a simple plasmosome.3. The spireme segments into thirteen parts, of which twelve form rings, the thirteenth becoming attached as a chromatin mass to the plasmosome, which at this stage is double.4. In the growth period, when the twelve rings are definitely formed, the chromatin mass is bent in a crescentic band around the plasmosome, forming a chromosome nucleolus.5. This band represents a pair of idiochromosomes, and is bivalent like the rings, but always appears as a single body.6. First and second metaphases show thirteen chromosomes. Divisions are equal, so that the spermatids contain similar chromosome groups. |
| Databáze: | OpenAIRE |
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