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Fig. 13. Stages in the spermatogenesis of a grasshopper (Stenobothrus viridulus)


1 - Spermatogonium in process of division, having 17 chromosomes (8 pairs and one odd).

2 - Representing growth period of spermatogonium.

3-6 - Division of the primary spermatocytes sixteen of the chromosomes are paired while the "accessory" has no mate and passes as a whole to one of the two secondary spermatocytes.

7-8 - Division of the secondary spermatocyte with the odd chromosome, the latter splitting and giving one-half to each resulting spermatid.

x, "Accessory" chromosome.

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Pages where the terms "Historic" (textbooks, papers, people, recommendations) appear on this site, and sections within pages where this disclaimer appears, indicate that the content and scientific understanding are specific to the time of publication. This means that while some scientific descriptions are still accurate, the terminology and interpretation of the developmental mechanisms reflect the understanding at the time of original publication and those of the preceding periods, these terms, interpretations and recommendations may not reflect our current scientific understanding.     (More? Embryology History | Historic Embryology Papers)


Bailey FR. and Miller AM. Text-Book of Embryology (1921) New York: William Wood and Co.

Cite this page: Hill, M.A. (2024, June 14) Embryology Bailey013.jpg. Retrieved from

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