234 

 for it. 



EMBRYOLOGY. 



But in the interest of a more precise definition it is advisable 



^ to use the name 



i f* 



only in the re- 

 stricted sense 

 in which it has 

 been employed 



/ 



Tig. 135a. Uterus of a Cow laid open, in the middle of the period of 



gestation. From BALFOUR, after COLIN. 

 V, Vagina ; U, uterus ; Ch, chorion ; C 1 , cotyledons of the uterus ; C 3 , total 



membrane or 

 chorion only. 

 The forma- 

 tion of the pla- 

 centa presents 

 in its details 

 important mo- 

 difications. 



Runii- 

 3, in which 

 the blastoder- 



mic vesicle is drawn out into two tips, as in the Pig, present a 



special type 



(fig. 135a). On 



their chorion 



(Ch) have been 



developed very 



many small 



foetal placentae 



(C 2 ), which here 



are also called 



cotyledons. The 



number of the 



latter is ex- 

 ceedingly vari- 

 able in the 



different SDe- Fi * g 135b -~ Cotyledon of a Cow, the foetal and maternal part* half 

 detached from each other. After COLIN, from BALFOUR. 

 Uterus ; C l , maternal part of the cotyledon (placenta uterina) ; 



cies, from sixty 

 to one hundred 

 in the Sheep 

 and Cow, and only from five to six in the Doe. They are united with 



Ch, chorion of the embryo; C". total part of the cotyledon 

 (chorion frondosum or placenta totalis). 



