MAMMALIA. 



I'll 



ridges on which are placed the openings of the uterine glands. The re- 

 maining Ungulata with diffused placentae do not differ in any important 

 particulars from those already described. 



The polycotyledoiiary form of placenta is found in the Ruminantia 

 alone. Its essential character consists in the fetal villi not being uni- 

 formly distributed, but collected into patches or cotyledons which form as 

 it were so many small placentas (fig. 157). The foetal villi of these patches 



Ch 



FIG. 157. UTERUS OF A Cow IN THE MIDDLE OF PREGNANCY LAID OPEN. (From Huxley 



after Colin. ) 

 T. vagina ; T. uterus ; Ch. chorion ; C 1 . uterine cotyledons -. C-. fnetal cotyledons. 



if 



%*A 



>-v\ "V Vff'.'j'-^,/,-^ />- ^Kfc-v. - ; 



'-K-^ ; -. ^ 1 : --^i^ 



^^^^^'^^j^^^^K \' 



^ ' ' v " ^^&^-;S 



^- 



FIG. 158. COTYLEDON OF A Cow, THE FCETAL AND MATERNAL PARTS HALF SEPARATED. 



(From Huxley after Colin.) 

 u. uterus; Ch. chorion; C 1 . maternal part of cotyledon; C-. t'uetal part. 



142 



