THK PLACENTA. 



87 



absent in an unimpregnated cornu, and in their stead were thousands 

 of the accessory processes grouped together in small clusters. The 

 whole of the lining membrane of this cornu had a peculiar mossy or 

 velvety appearance. In a number of instances Franck has observed, in 

 the immediate neighbourhood of the os uteri, where cotyledons proper 

 were absent, groups of the so-called accessory cotyledons, in their form 

 representing a j^lacenta i^rcevia (Figs. 53, 54). Certainly, this kind of 

 •placenta prccvia in Cattle has not the disadvantages it offers in woman ; 

 for although a premature delivery may occur, a sufhciency of the 

 placenta always remains to maintain the nourishment of the foetus. 

 Serious hicmorrhage is likewise little to be apprehended in such cases ; 

 and even disconnection between the placenta foctalis and the placenta 

 uterina in the Cow causes no injury. This is not the case with the 

 human female and the Bitch. Small haemorrhage streaks at the summit 

 of the finer tufts, or on their upper surface, are often noticed in the 



Fig. 51. 



ToKTiON OK Chorion with Placentll.*: : Cow. 



1, Chorion ; 2, Placentulae. 



uterus of Cows which have been slaughtered and bled. Birnbaum 

 attributed these streaks to a plethora ex vacuo} 



The accessory placentuko, are, both in shape and situation, as well as 

 in development, different from the cotyledons proper ; for while the 

 latter, and of course also the foetal cotyledons, are arranged in four 

 regular rows, in the gravid uterus, through the rapid increase of the 

 amnion towards the poles of the ovum, they lie somewhat closely to- 

 gether, and the accessory processes are placed between these rows in 

 an irregular manner. In their highest development, the latter are so 

 disposed as to constitute a variable-sized, felt-like patch ; the largest 

 and widest are usually observed behind the ordinary cotyledons, and 

 their form is very irregular, but normal. As a rule, the largest are not 

 so big as a walnut, and they are widest at their base. In structure they 

 resemble the ordinary cotyledons, their bloodvessels being arranged in 

 the same manner, while they are covered externally by a sheatli of 

 epithelium. In the early period of pregnancy — about the second or 

 third month — they are found in largest number on the entire upper 

 surface of the chorion, also on the parts between the oi-dinary coty- 

 ^ Untersuchungtn i'lf/er deu Ban dtr EihdiUe der Saugthiere, p. 90. 



