HUMAN MALE MONSTER. 224 
We therefore muft conclude, that the circulation of the 
blood in the placenta and body of the monfter, was carried on 
by a well regulated mufcular action of the blood-veffels. In 
one of the worms, the echinus efculentus, I found in the me- 
-fentery, which is a principal part of it, two fuch large veffels 
without a heart, and which, we can fcarcely doubt, refembled 
our aorta and cava, and circulated its fluid; and in fithes*, 
the blood which paffes through the liver defcribes three circles, 
and in all other parts of the fifh the blood defcribes two circles 
before it returns to the heart; which motion of it we muft 
fauppofe to be chiefly owing to the mufcular action of the 
veffels, as the force of the heart appears to be as much fpent 
in the gills of the fifh as in the lungs of a man. 
From confidering the manner and caufe of the motion of the 
blood in this monfter, and comparing with it the motion of 
the blood in fifhes and in the fea egg, we are, by analogy, led to. 
the following general concluftons : 
1. THE arteries contribute much to the circulation of the 
blood in our bodies. 
2. IT is probable that, in man, the veins likewife affift in cir- 
culation ; and, in particular, there can be no doubt, that the 
vena portarum, by its action, contributes much to the motion 
of the blood through our liver. 
3. For the like reafons, we may conclude, that arterious 
veffels, independent of the impulfe of the heart, may act in 
~ fuch a manner, as to perform the fecretion of liquors, to nourith 
the folids, and to add to their bulk; and particularly, that the 
branches of the vena portarum change certain parts of the 
blood into bile. ; 
‘FP fs Remarks: 
' * See Monao on Fifhes, p. 64. Tav.. xliii.. 
