of a Human Foetus. 1S7 
Dr. Clarke* has given an account of a case, in which a 
woman, after a natural labour, was delivered of a healthy 
child, and also of a substance covered by common integu- 
ments, of an oval form, four inches in length, and having a 
separate navel string and placenta. In this substance there 
was one os innominatum, with a femur, tibia,-and fibula. There 
were neither brain nor nerves ; nor were there any viscera, 
except a small portion of intestine. The umbilical chord con- 
sisted of two vessels, an artery and a vein, both of which 
ramified in this substance and in the placenta. 
In Dr. Hunter's anatomical collection, there are two spe- 
cimens of monsters born without hearts. In both of them the 
whole upper part of the body was wanting ; and in neither 
was the exact nature of the circulation ascertained. 
In each of the instances which I have quoted, not only the 
heart was wanting, but the foetus in other respects was so im- 
perfect, that it could not be considered as any thing more than 
a mola, or an irregularly formed living mass connected with 
the placenta. In particular, in all of them the brain, which may 
with justice be considered as affording the best distinction be- 
tween a mola and a foetus, was wanting ; whereas in that which 
forms the subject of the present paper, the brain was nearly as 
large as usual, and in other respects the foetus varied much 
less from the natural structure, than in any former instance. 
In the cases already on record, we have seen, that where- 
ever the size of the monster was mentioned, it was much 
smaller than a natural foetus. This would have led to the 
supposition, that a circulation, which was carried on by the 
action of the vessels only, was incapable of maintaining the 
• Phil. Trans, for 1793. 
