SPERMATOGENESIS— INSEMINATION 



169 



support and as a means of conveying nourishment to the growing 

 spermatozoa.^ The tails of the latter at this stage project 

 freely into the cavity of the tubule, and a httle later the sper- 

 matozoa shift bodily forward and become completely hberated. 



Fig. 42.— Section through portion of two seminiferous tubules in testis 



of rat. 



ct, basement membrane ; b, spermatogonium ; e, spermatocyte ; d, sper- 

 matozoa in cavity of tubule ; e, interstitial tissue containing vessels. 



' Merkel, " Die StUtzellen des Menschlichen Hodens," MiUler's Arohiv, 

 1871. Brown, "On Spermatogenesis in the Rat," Quar. Jour. Micr. Science, 

 vol. XXV., 1885. Bende, " Untersuohungen tiber den Bau den Funktioniren den 

 Samenkanalchens einiger Saugethiere," Arch. f. Mih: Anat., vol. xxx., 

 1887. 



