VOL. LVII.] PHILOSOPHICAL TRANSACTrONS. 3^7 



sition seems too much against nature to counterbalance the other opinion, which 

 makes the trunk e of the aorta, a portion of the umbilical vein, and the substi- 

 tute of the heart. 



Another anatomical fact proves this last opinion ; which is, that the aorta, and 

 especially the superior, f, ran up as high as the cranium, and was of a pretty 

 considerable size, while the venal trunk, d, had nothing but capillary branches 

 in the upper parts; so that it almost appeared evident that the vessel ep was con- 

 nected with the chief mover of the fluids. Therefore, supposing the trunk d 

 to be the vena porta, or aVi imperfect cava going to some of the viscera, being 

 the rudiments of an imperfect heart, or a vena cava ending in a pouch, as the 

 intestines did which should have entered the stomach, if there had been one; the 

 difficulty almost disappears. He says almost, because, even on this supposition, 

 if there was a circulation in this monster, we must admit some anastomoses, 

 between the arterial and venal system, which supplied those found in other foe- 

 tuses; since the venal blood must in some place or other re-enter the arterial 

 torrent. Such might be the anastomosis k*, fig. 8. For, by this hypothesis, 

 the vascular system of this subject would be represented by this fig. 8 thus : 



A The umbilical cord; b the intestinal tube; d the kidney liver; e a sort of 

 glandula renalis; a the umbilical vein : the great mover of the fluids; b the aorta, 

 a continuation of that vein; cd aorta superior, accompanied by the vena cava; 

 e aorta inferior; f the distribution of the iliac; g the umbilical arteries, making 

 a part of the distribution ; h the trunk of the vena cava coming either from the 

 portae, or from the viscus d, or forming a blind pouch in that part; some traces 

 of the vena cava superior appear towards c ; i the cava inferior going to form the 

 iliacs ; k a necessary anastomosis between the two kinds of vessels, arteries, and 

 veins. 



He repeats it again, if he had but suspected so many singularities, what he 

 now could give only by way of conjecture, might have become demonstrable in 

 fact. It was scarcely probable that he should ever have such another opportunity; 

 but it was more so, that it might offer to some one among the great number of 

 the literati in Europe, who read the Philos. Trans. This was the principal motive 

 that determined him to present this observation, though imperfect, to the r. s. 



Another motive, which engaged him to offer this observation, such as it was, 

 was, that even the imperfection of it did not affect the useful consequences de- 

 ducible from it; for whatever may have been the disposition of the blood vessels 

 of this monster, it is a fact absolutely certain, that it had no heart, nor any other 

 viscus in the place of it; and that the circulation of the fluids, which appears to 



• Several letters of reference will be found in this paper which are not engraven on the plate : 

 they were omitted from the plate in the original Transaction*. 



