84 OBSTETRICAL PHYSIOLOGY, 



nal fluid, as well as in that on the surface of the uterine mucous mem- 

 brane of a Mare towards the end of pregnancy, Ercolani has demon- 

 strated the presence of albumen ; in the same fluid he has also proved 

 the existence of amidon, dextrin, and sodium chloride.* 



The reticulated surface of the maternal cotyledons is hornologous with 

 the decidua serotina or other mammals ; but it possesses a firmer texture, 

 and usually remains attached until the termination of gestation — allowing 

 the foetal villi to be withdrawn from it at birth ; it is afterwards shed or 

 disappears in some obscure manner, and the caruncle again assumes its 

 smooth surface. 



As in solipeds, there is no direct vascular communication between the 

 maternal and foetal cotyledons, the villi of each being distinct, though in 

 close contact ; being only separated at points by the lattescent fluid just 

 alluded to. This fluid, which is present in all the domesticated animals, 

 can be readily discovered by carefully withdrawing a chorionic tuft from 

 the alveolar cavities of the uterine cotvledon. 



Pig- 43- 



Cotyledon of a Cow's Uterus. 



aa, Surface of Foetal Chorion ; bb. Blood-vessels of Foetal Chorion ; cc. Surface of Uterine 

 Mucous Membrane ; dd. Blood-vessels of ditto ; /, Secretion from Utricular Glands — Cotyle- 

 donous Milk — between Maternal and Foetal Vessels, and which is necessary to the Mutual 

 Interchange of Gases, and Nutrient, Effete, and other Matters between Parent and Offspring. 



Sheep and Goat. 



In the Sheep and Goat the arrangement of the placenta is essentially- 

 the same as in the Cow, except that the maternal cotyledons are deeply 

 concave or cup-shaped in the middle, and into this cavity the foetal 

 placentula is received and closely retained. This placentula is not so 

 wide as that of the Cow, though it is thicker and the villi are more 



♦ We must not overlook the fact, that the existence of the " uterine milk "in the living pregnant 

 animal has been denied by M. CoWn (Traite de Fhysiologie Comparie des A nimaux, 1872, vol. II., P- 

 870), who states that this fluid is simply a product of cadaveric decomposition, and is not found during 

 life ; as he has assured himself in the most evident manner, by opening the uterus of a pregnant Mare and 

 Cow. It is not found immediately after death, as he has demonstrated on m^ny occasions, in Cows and 

 Sheep slaughtered in the abbatoirs at all periods of gestation ; it is not even observed six, twelve, or 

 twenty-four hours, or longer, when the surrounding temperature does not favor decomposition. It is only 

 when the placentas spontaneously separate, or are disunited by slight traction, at a greater or less time 

 after death, according to circumstances, that the white or yellowish-red colored fluid appears between the 

 chorion and uterine mucous membrane. In proportion as decomposition has advanced, the fluid is abun- 

 dant. Colin therefore concludes that it is a product of softening and progressive dissolution of the uterine 

 mucous membrane and its cotyledons, as well as the placentae themselves. 



