SPERMATOGENESIS— INSEMINATION 



i6i 



In embryonic development the tubules arise from the primitive 

 germinal epithelium. According to Allen i the interstitial cells are 

 derived from connective tissue. 



The straight tubules, aiid the tubules of the rete, are lined by a 





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h P 



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Fig. 47. — Section through te.stis of monkey. 



«, Semiiiifei'ous tubule.s ; /<, interstitial tissue ; .;■, rete testis ; iJ, vasa 

 efferentia ; <\ vas defeiens ; /', tunica albuginea. 



single layer of cubical or flattened epithelium without a basement- 

 membrane. The seminiferous tubules, on the other hand, contain 

 several layers of epithelial cells supported by a thick basement- 



' Allen, "The Embryonic Development of the Ovary and Testis," Amer. 

 Jmir. of Anat., vol. iii., 1904. As already mentioned, Allen regards the inter- 

 stitial cells of the ovary as being developed from connecti\'e tissue, tlius difleiing 

 from Miss Lane-Claypon. 



