312 



PHYSIOLOGY OF GONADS 



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Fig. 5.3. Developmental stages in the monkey testis {continued jrom Figure 5.2) 



19. Testis of 110-day fetus. Note short, uncoiled tubules, with a diameter of 70 to 80 ti. 

 Cytoiilasm of Sertoli cells is well developed and largely fills the lumen. The broad inter- 

 tubular spaces contain abundant cells, many of which are enlarged and roun<led. 



20. Testis of 110-day fetus. This shows tubules in cross section. The orientation of the 

 interstitial tissue concentrically around the tubules and the enlargement of the cells within 

 the concentric rings are evident. 



21. Testis at birth after a 174-day gestation. Note the Sertoli nuclei remaining in a basal 

 position and the persistent wide intertubular space; however, the size of the Leydig cells 

 has decreased. 



22. Right testis at 2 years, 10 months, 3 days. Tubular diameter is 100 to 120 fi. Spermatids 

 have differentiated to presperm cells or almost mature sperm cells. Great amounts of cellular 

 debris fill the lumen. Few Leydig cells are differentiated. 



23. Right testis 1 month later, at 2 years, 11 months, 1 day. Tubular diameter is 100 to 

 140 fi. Sperm cells are present. 



