168 



PHYSIOLOGY OF FARM ANIMALS 



[CH. 



surrounded by unstriated muscular tissue which is arranged in 

 two (or three) layers, the inner layer consisting of circular aiid 

 the outer of longitudinal fibres. Connective tissue with good sized 

 vessels is also present in the muscular layers. Outside of all is 

 the serous or peritoneal coat. 



The Vagina into Avhich the male organ penetrates during coitus 

 extends from the uterus to the exterior opening. Its walls contain 





W^l^^' 



Fig. 82. Section through vagina of monkey (from Marshall), o epithelium, 

 b sub-mucous layer, c lymphatic gland, d nerve, e sensory end-organ, f fat cells. 



longitudinal and circular muscle fibres, and internally it is lined 

 by a stratified scaly epithelium. The female generative organs 



