358 Dr Craigiu's Observations on the 



the raultifid arrangement of that organ in quadrupeds, and the 

 bifid arrangement in birds. The accuracy of these observations 

 will be lecognised by the comparative anatomist. In most of 

 mammiferous quadrupeds, excepting a few of the monkey tribe, 

 the liver consists of four or five lobes, separated by very deep 

 fissures, so as to be completely detached from each other ; and 

 in birds, the same organ consists of two lobes, which are gene- 

 rally nearly equal in size. But in his further account of the 

 organ, he is led to give a description of the venous system, in 

 which he repeats most of the errors of the ancients. 



The account of the anatomy of the heart and brain is greatly 

 better, and indeed is the best part of the treatise of Columbus, 

 excepting one passage, where, in accordance with his views in 

 the sixth book, he represents the artenous vein to arise, not from 

 the heart, but from the liver. While he falls into this error, 

 however, he has the courage to show, in opposition, not only 

 to the authority of Galen, but of most anatomical teachers at 

 that time, that this vessel contains not air, but blood mixed 

 with air, which it receives from the lungs, and thus conveys to 

 the left ventricle. To these views he appears to have been led 

 chiefly by opening the bodies of living animals, and observing 

 the heart and vessels in action. He contends, in opposition to 

 Aristotle, that the blood is not formed in the heart ; and he 

 justly remarks, that no bone is found in the human heart, as 

 in those of the ox, buffalo, horse, elephant, and other large 

 animals. 



His sketch of the distribution of the arteries is correct, and 

 that of the course of the circulation shcw^s that he was the first 

 who had formed ideas of that function rather more distinct than 

 those of Servet. He distinguishes two kinds of blood, natural 

 (sanguis naturalis), and aerated or prepared {sanguis spiri- 

 tuosus vcl paratus) ; the first corresponding to the venous or 

 circulated, the second to the arterial or respired blood of modern 

 physiology. The first, he says, is received from the vena cava 

 into the right ventricle, while the second is received from the 

 venous artery into the left ventricle, while the membranous 

 folds or valves yield and allow its entrance. On the contrac- 

 tion of the heart, these valves are again shut, to prevent the 

 blood from receding ; and at the same time the valves both of 

 the large artery, aorta, and of the artcrious vein (pulmonary 



