MODIFICATloXS IX THE UTEJiL'S. 



129 



Uterus coiTcsponcling to the fa'tal i>laceuta. So that, at least in the 

 early months of pregnancy, it is thinnest towards the cervix. The 

 increased thickness of the organ, however, never equals that observed 

 in the human female, compared with which the walls of the uterus of 

 the domesticated animals are thin. 



The firmness or density of the organ is always most conspicuous in 

 the cornua, and in the operation of "spaying," or castration of the 

 female, this serves as a useful guide in enabling the operator to distin- 

 guish between them and the intestines, which they so closely resemble 

 in appearance. 



But during pregnancy this density seems to diminish as the organ 



Fig. 64. 



Vertical Section through a Portion ok thk Uterine Cotylkoon or a 

 Cow IN AN Eaui.t Stage of IMiegnancy. 



o, Serous Membrane ; h. Section of Longitudinal Muscular Layer ; c, External, 

 and (•', Internal Layers of the Circular Muscle ; '/, SuWmucoxa, with Vessels ; 

 C, Adenoid Tis-un i,f the Cotyledon ; /' New Tissue of the Placenta Uterina ; 

 g. Section of the Mucous Lajer of the Cntyledon, with the Interspaces into 

 which the Fatal Cotyledons are inserted ; //, h, I'tricular tJlands piutsing 

 iinder the Side of the Cotyledon ; i, i. Large Cotyledonal Vessels ; k, Uterina 

 Mucosa ; /, /, Epitht-lial Layer of the Cotyledon. 



becomes more vascular, and the cervix assumes a much softer condition 

 than usual. For instance, in the ftetal cornu of a Cow advanced three 

 months in pregnancy, the thickness of the wall was only 2*0 milli- 

 metres, while in the other horn it was 4 millimetres. In another 

 Cow at five months, it was 4 millimetres in the foetal horn and 5 

 millimetres in the vacant one. The mucosa is thicker, redder, more 

 pulpy and vascular, than before impregnation ; the longitudinal rugai it 

 then exhibited gradually disappear ; the epithelium covering it usually 

 loses its columnar form ; the utricular glands enlarge — they are longer 

 and their orifices wider, and their secretion, as well as that of the other 

 glands, is increased ; the interglandular tissue is largely and rapidly 

 augmented by multiplication of the ceils of the surface epithelium, and 



