48 Account of the Dhsection of a Human Focitn.: 

 Dienfs, of an oval form, four inches in length, and havin^^ 

 separate navel string and placenta. In this substance there 

 was one os innominatum, with a femur, tibia, and fibula. 

 There were neither brain nof nerves ; nor were there any 

 viscera, except a small portion of intestine. The umbilical 

 chord consisted 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 instau-i-s which I have quoted, not only 

 the heart was wanting, but the foetus in other respects was 

 so imperfect, 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 afford-^ 

 ing the best distinction between a mola and a foetus, was 

 wanting; whereas in that which forms the subject of the 

 nresent 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 muchf 

 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 

 natural growth of a child, had it not been found that the 

 foetus, which I have described, tliough the heart was want- 

 ing, was fullv equal in size to a fceius of the same age 

 which was possessed of that organ. 



It may be observed, that in all these cases, in which the 

 heart was wanting, the liver was wanting also. It is probable, 

 that the action of the vessels only, without the assistance of 

 the heart, would have been insufficient to propel the blood 

 through the circulation of the livef;, which is so extensive ia 

 the natural foetus. 



Vllt. Geo- 



