210 



PLACENTA OF THE. UNO U LATA. 



glands of the uterus open (tig. 155 g) (Turner). The maternal and fietai 

 parts of the placenta in the pig separate with very great ease. 



cr cr 



Fig. loo. Surface-view of the injected uterine mucosa of a gravid Pig. (From 



Turner.) 

 The fig. shews a circular non-vascular spot where a gland opens (//) surrounded by 

 numerous vascular crypts {cr). 



In the mare (Turner), the foetal villi are arranged in a less definite 

 zonary band than in the pig, though still absent for a very small area at 

 both poles of the chorion, and also opposite the os uteri. The filiform villi, 

 though to the naked eye uniformly scattered, are, when magnified, found to 

 be clustered together in minute cotyledons, which fit into corresponding 

 uterine crypts (tig. 156). Surrounding the uterine crypts are reticulate 



Fig. 156. Vertical section through the injected placenta of a Mare. 

 (From Turner.) 

 ch. chorion with its villi partly in situ and partly drawn out of the crypts {cr). 

 K. loose epithelial cells which formed the liniug of 'the crypt; g. uterine glands; 

 V. blood-vessels. 



