Chap, xiii.] MALE DUCTS. 519 



hedgehog, and the remaining portions of the ducts, or 

 so-called cormia iiteri, are long ; (3) in the mare 

 the cornua are proportionately shorter ; and (4) in 

 the highest forms, as in man, the short proximal 

 portions of the oviducts ("Fallopian tubes") open 

 directly into the large single uterus. 



As has already been pointed out (see page 263), 

 the male have a different origin to the female 

 generative ducts of Vertebrates, arising, as they do, 

 from the primitive Wolffian duct. On the whole 

 they present less important points of difference in 

 various groups than do the oviducts ; and they con- 

 stantly remain separate along the whole of their 

 course ; where there is a terminal portion which ap- 

 pears to be single, it is not part of the Wolffian duct. 



In the ichthyoid vertebrates the seminal products 

 always make their way through the kidney ; in the 

 lizard the testicular duct (vas defereiis) and the 

 ureter only unite just before they open into the cloaca. 

 In Birds the two ducts run close to, but open sepa- 

 rately from, one another. In the Monotremata the 

 renal and seminal ducts open separately into the 

 cloaca, and the common urine-genital passage is distal 

 to it. 



In the remaining Mammalia, where the ureters 

 open separately into the bladder, there is, again, no 

 relation between them and the Wolffian ducts ; in 

 place thereof, however, we find -a common passage, 

 the vasa deferentia, opening at some point on the 

 course of the urethra, which is itself the narrowest 

 proximal end of the allantois. 



Copulation is not always effected among fishes, 

 some only discharging their genital products into the 

 water ; in the Elasmobranchs the hinder pair of fins 

 serve as organs for dilating the female orifice, and 

 between them there is placed a papilla, on which 

 the seminal ducts open, and this is inserted into 



