4i6 



THE EVOLUTION OF MAN. 



become oviducts, traces of the Wolffian ducts remain, and 

 are known as " Gartner's canals." 



'iiri"Ti'"«r,«i,'^)^''^"iv 



3. 



FlOS. 324-326. — Urinary and sexnal organs of an embryonic Ox. Fig. 

 324, of female embryo of 1^ inch in length ; Pig. 325, of male embryo 

 of 24 inches in length ; Fig. 326, of female embryo of 2^ inches in length : 

 w, primitive kidney ; wg, Wolff's duct ; n», Miiller's duct ; m', upper end of 

 he latter (opened at <)> *> lower thickened end of the same (rudiment 

 of otenu) ; g, genital cord j h, testes {h', lower, h", upper testis-oord) ; 

 0, orary ; 0', lower ovary-cord ; t, groin-cord of the primitive kidney ; 

 d, diaphragm>oord of the primitive kidney ; n, permanent kidneys (below 

 these the S-shaped urine-duct ; between the two the reotmn) ; v, urine- 

 bladd«r ; a, navel-artery. (After KSlliker.) 



The most interesting facts in reference to this remark- 

 able development of the primitive kidney ducts and their 

 anion with the sexual glands are exhibited in Amphibia 

 (Figs. 321-323). The first rudiment of the primitive kidney 

 ducts and their differentiation into the Miillerian and 



