104 ARISTOTLE'S DISSECTIONS. 



with the question of Aristotle's dissections, it will be neces- 

 sary to discuss them at some length. 



The heart, Aristotle says, is more to the left side in 

 Man, being inclined a little away from the middle line, in 

 the upper part of the chest, towards the left breast.* This 

 is substantially correct, for about two-thirds of the volume 

 of the heart lies to the left of the median plane and its apex 

 is directed towards the lower part of the left breast. The 

 description may have been written, however, after an exami- 

 nation of the position of the heart of one of the lower 

 animals, supplemented by an external examination of the 

 part of the human chest against which the heart seems to 

 beat. It is evident that the beat of the heart, usually per- 

 ceptible about three inches to the left of the median plane 

 and in the fifth intercostal space, would suggest that the 

 heart lies more on the left side of the chest. Galen says 

 that it was on this account that the heart was believed to be 

 on the left side ; he himself believed that the heart was in a 

 central position.! 



Another passage sometimes cited to show that Aristotle 

 dissected the human body is that in which he says that it is 

 not without feelings of repugnance that we see blood, flesh, 

 bones, blood-vessels, and other parts in the human body. + 

 This passage seems to cut both ways ; it is as much against 

 as for the opinion that Aristotle dissected the human body. 



It appears, therefore, that Aristotle's writings do not 

 prove that he dissected the human body ; on the contrary, 

 they contain many statements which suggest that he never 

 did so. With respect to the human foetus, he seems to have 

 dissected it, if only to a small extent. He says that if the 

 human embryo, aborted after forty days, be put into cold 

 water it becomes surrounded by a membrane, and that, if 

 this be dissected away, the embryo appears to be of the size 

 of a large ant, all its parts being visible and its eyes being 

 large. § Again, he makes some statements, e.g., that the 

 human kidneys are lobulated, which are true of the human 

 foetus. 



Turning to the evidence obtainable from sources other 

 than Aristotle's writings, it will be seen that there is a 

 strong presumption against the probability that he ever dis- 

 sected the human body. Among the Greeks a feeling of 



■■■' H. A. i. c. 14, s. 2, ii. c. 12, s. 2 ; P. A. iii. c. 4, 66G6. 

 f De Usu Partium, vi. 2. I P A. i. c. 5, 645rt. 



IH. A. vii. c. 3, s. 4. 



