PHYSICAL awn LITERARY. 422 
the womb ; while in our prefent fubjet, and 
—thofe of Vater and Albinus, the placenta was 
fixed to the back part of it, and Dr Smellie 
aflures me, he has found it attached to the 
os uteri. Y think therefore it is plain, that 
there is no particular part to which we can 
fay the placenta is always fixed: from which 
it may be juftly concluded, that the chorion is 
not all equally capable of being placenta; and 
_ that the placenta does not owe its exiftence to 
the energy of any particular {pot of the . 
womb; but that it is an original part which 
adheres to whatever place, not only of the 
womb, but of the Fallopian tubes * or abdo- 
men, + it happensto be contiguous to ; where 
it caufes a confiderable flow of liquors, by the 
abforbing powers of its veffels ; in the fame 
way as the fucking of the nipple is the moft 
effectual way of caufing a flow of milk to 
the breafts. ‘Thus the part of the human 
womb where the placenta is applied, has its 
extreme veins enlarged into fimufés: and the 
. f{mooth furface of the womb and its cornua 
in cows, is raifed into glandular-like bodies 
where each placenta is placed. 
THO’ 
* See two examples.of this.in De Graar de mulier. orga- 
his cap. xiv. quoted from Rioran. 
_ t An example of this, in Hif?, de 2? Acad. des Sciences 1716+ 
