CHAPTEE XV 



THE EEPKODUCTIVE SYSTEM 



GENERAL CONSIDERATIONS 



The reproductive system differs structurally, widely in the two 

 sexes. The several organs involved, however, are in general strictly 

 homologous in the male and female organism. The differences result 

 from a divergent specialization concomitant with a division of labor 

 in the reproductive act and process. The specialization involves both 

 progressive and regressive differentiation, the latter producing certain 



SinuS 



Corf"" 



Ct f /!* 

 ft/tit 



J)uetu/u3 



J)uctus r/n. Ji </ m i 



Cc't> Ct/. urethr 



Clar! penis 



fosse,. nen'e* t 



flfptna 



i C/L ffy fni S 



FIG. 418. DIAGRAM OF MALE GENITALIA. (Adapted from Merkel.) 



vestigial appendages, of different origin in the opposite sexes. The 

 MALE ORGANS OF REPRODUCTION include a primarily and essentially in- 

 ternal group of genital organs, namely, the testis, and its associated 

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