of a Human Foetus. 163 
composed internally of a dense cellular substance. The oeso- 
phagus had the usual situation, but it terminated in a cul-de- 
sac at the lower part of the thorax. The rest of the thorax 
was filled with a dense cellular substance ; and in place of 
the diaphragm, there was a membranous septum between it 
and the cavity of the abdomen. 
In the abdomen, the stomach had no cardiac orifice. The 
intestine was attached to the mesentery in the usual way ; but 
it was proportionably shorter than natural. There was an 
imperfect coecum, but the colon was not distinguished by any 
difference of structure or appearance from the rest of the in- 
testine. The rectum had its usual situation in the pelvis. The 
spleen and renal capsules were small ; the kidnies, bladder, 
penis, and testicles had the usual appearance. The abdomen 
was lined by peritonaeum, but there was no omentum. The 
liver and gall-bladder were wanting. 
As there was no heart, it became an object of importance 
to ascertain the exact nature of the circulation : for this pur- 
pose, the blood-vessels were traced with attention. 
The umbilical chord consisted of two vessels only : one of 
these was larger than the other, and its coats resembled those 
of a vein, while those of the smaller vessel were thick and 
elastic, like those of an artery. Both of these vessels entered 
the navel of the child. The artery passed to the left groin by 
the side of the urachus, occupying the usual situation of the 
left umbilical artery. Here it gave off the external and inter- 
nal iliac arteries of the left side, and was then continued up- 
wards on the fore-part of the spine forming the aorta. From 
the aorta arose the common trunk of the right iliac artery, 
and the branches to the viscera and parietes of the thorax and 
Ys 
