THE PLACENTA. 563 



Of the Placenta. 



In my opinion, then, the placenta and carunculse have an office 

 analogous to that of the liver and mamma. The liver elaborates 

 for the nourishment of the body, the chyle previously taken 

 up from the intestines : the placenta, in like manner, prepares 

 for the foetus alimentary matters which have come from the 

 mother. The mammae also, which are of a glandular structure, 

 swell with milk, and although in some animals they are not 

 even visible at other times, they become full and tumid at the 

 period of pregnancy; so, too, the placenta, a loose and fungus- 

 like body, abounds in an albuminous fluid, and is only to be 

 found at the period of pregnancy. The liver, I say, then, is the 

 nutrient organ of the body in which it is found; the mamma 

 is the same of the infant, and the placenta of the embryo. And 

 just as the mother forms more milk from her food than is requi- 

 site to sustain her own flesh and blood, which milk is digested 

 and elaborated in the mamma ; so do those animals, furnished 

 with a placenta, supply to the foetus nourishment which is puri- 

 fied in that organ. Hence it happens that the embryo is furnished 

 with good or bad nutriment just as the mother takes wholesome 

 or unwholesome food, and in proportion as it is elaborately pre- 

 pared or not in these uterine structures. For some embryos 

 have a more perfect structure provided for them, such as that 

 fleshy substance mentioned above, which in some is altogether 

 wanting. In some, also, the placenta is observed to be thicker, 

 larger, and more loaded with blood ; whilst in others it is more 

 spongy and white, like the thymus or pancreas. But there is 

 not more variety found in the placenta than in the mamma or 

 viscera generally : for instance, the liver in some animals is red 

 and filled with blood, in others, as is the case with fishes and 

 some cachectic persons in the human species, it is of much paler 

 hue. The mare feeds on crude grass, and does not ruminate ; 

 the sow gorges itself with any unclean food ; and in both the 

 placenta, or organ for perfecting the aliment, is wanting. 



Rightly then is it observed by Fabricius, 1 that " this fleshy 



1 Cap. iii. 



