Tin: OB6ANB or TIN-: MIDDI.I. UEKM i 





the four duct> are united b -hind tin- bladder (/////) into 



ialcord', this muon is due to their becoming >un-ounded l.y the 



umbilical arteiiefl which have :it thi> time attained ;. . ;iinl 



which run from tin- aorta mi 1 >tii 



siil. > of the bladder up to the 



uml>ilicus and to their being, as 



it \vi re, tied up intu a bundle by 



them. In a cro Mvtion through 



the gi nital cord (L. e find 



the nu'soiM-pliiir lu.-t> (</) -<un- 



what inoi-f anterior | ventral] and 



at tin- >nmi- tiinr fartln-r aj>ait 



tlian tin- Miillt-rian ducts 



\vliicli ;.!(' a little hrhind them 



a in I pressed quite close together 



in the median plant-. 



In older embryos there ari>e 

 in the evolution of the iiroirenu.-.l 

 in differences between the 

 two 96X66 which are \ i>il)i- e\.'n 

 extt-i-nally and which become 

 more distinct from month to 



month. The>e result from fundamental metamorphosis, which the 

 whole appai atu> continually undergoes in its srparat- part-. lj : 

 connection with tlii- sonic originally ^uite large fundament.^ undergo 

 almost complete d vfnM-at ion ; of tlio-- which remain some an- 

 M-rvic. ahlo only in the female, others only in the male; when not 

 employed, they disappear. .Moivov.-r the conditions which wei>- 

 reternd to at the iK-ginning of the docript ion are e\ten>ively edl 

 by tin- fact that the >e\ual organ> surrendei- their original position. 

 :t her >id of tlu lumbar vertebra-, and move farther downward 

 into tin- pelvic cavity. 



-.rib,, first the changes in the male, then those in the female. 





Fig. 220 Urinary and sexual organs of a 

 human embryo 8 weeks old, attt-r Ki>L- 

 I.:KI:H. Mamiit; :*, and 



seen fr<>m th^ \cntr;il I 

 Right suprarenal body; un, primitive 

 ; ung, mesoneptiric 

 duct ; ;; 



ligament (gubeni.-uuluni 11 

 mentuni .lum) ; >, 



b, bladder ; led, sexual gla 



(A) Thf Metamorphosi* in /// Male. Descemua tcm. 



\Vherea> th- igB, -- 1 and _ ) L ) _ ) )by conglomeration of the 



seminal tubules becomes a bulky organ (/<). the me-oiiephr.- 

 i> retarded in its development more and more, and i> at the same 

 time ditl'erently metamorphosed in its anterior and erior 



portions. The anterior or fCXUal j>'.i.--t e/' the, jirimitice kidney 



