394 
fact that Macrobius (vu. 14) ascribes to Erasistratus and 
Herophilus, two celebrated physicians of the succeeding gene- 
ration, the practice not only of dissection but of vivisection of 
human bodies, shews, if the story is true, that public opinion 
could not have been quite unprepared for it. 
Mr Pearson also referred to a passage in the Lincyc. Britan., 
art. Comp. Anatomy (§§ 202—205), ed. 1810 (but not occurring 
in later editions), in which the preferential use of the right 
hand is discussed, and ascribed to a natural peculiarity in the 
form of the sub-clavian and carotid arteries on that side: and 
in which it is stated that a similar preference for the right side 
may be traced in some dogs if not in horses. The speaker said, 
however, that he would not answer for the existence of such a 
preference himself in those animals, nor in the lion and camel, 
to which Aristotle (and Pliny after him) especially ascribe it. 
He concluded by exhibiting a lobster; a kind of shell-fish of 
which the right claw is distinctly larger and stronger than the 
left, as is specially mentioned by Aristotle (ot KapKwvol...t)v 
deElav eyovor yndyv pelo Kab loxyupotépay...). 
In conclusion an opinion was expressed that the preferential 
use of the right arm might be due to a natural shrinking from the 
use of the side nearest the heart, or perhaps a natural wish to pro- 
tect it as being, to our own sensations at least, the seat of vitality. 
At any rate such a use must be accepted as a fact, whether the 
more strictly anatomical reasons given in the former paper 
were correct or not, and the difficulty of coming to a conclusive 
view on the subject was suggested as a reason why the point is 
so little discussed, at any rate in the more popular and simpler 
treatises on anatomy: nor had the speaker been successful in 
finding much information on another question: viz., the true 
position of the heart in animals, Aristotle’s view on this point 
being very decided, while the practice of dissecting them was 
evidently common in his time: but still he ventured to think 
that the situation of the centre of gravity of the human heart 
