ARISTOTLE AS A BIOLOGIST 23 



central, or primary sense, and so locating in it the central 

 seat of the soul. And so it was held to be till Harvey's 

 time, who, noting the contemporaneous appearance of 

 heart and blood, held that the contained was nobler than*? 

 that which contained it, and that it was the blood that was ( 

 ' the fountain of life, the first to live, the last to die, the 

 primary seat of the soul, the element in which, as in a 

 fountain-head, the heat first and most abounds and 

 flourishes ' ; so harking back to a physiology more 

 ancient than Aristotle's ' for the blood is the life thereof.' 7 ) 

 All students of the Timaeus know that here Aristotle 

 parted company with Plato, who, following Hippocrates, 

 and Democritus, and others, placed the seat of sensation, 

 the sovereign part of the soul, in the brain. Right or 

 wrong, it was on observation, and on his rarer use of 

 experiment, 1 that Aristotle relied. The wasp or the 

 centipede still lives when either head or tail is amputated, 

 the tortoise's heart beats when removed from the body, 

 and the heart is the centre from which the blood-vessels 

 spring. To these arguments Aristotle added the more 

 idealistic belief that the seat of the soul, the ruling force 

 of the body, must appropriately lie in the centre : and he 

 found further confirmation of this view from a study of 

 the embryo plant, where in the centre, between the seed- 

 leaves, is the point from which stem and root grow. And 

 Ogle reminds us how, until a hundred years ago, botanists 

 still retained an affectionate and superstitious regard for 

 that portion of the plant, calling it now cor, now cerebrum, 

 the plant's heart or brain. 



And now is it possible to trace directly the influence of 

 Aristotle's scientific training and biological learning upon 



1 Aristotle's experiments were akin to Voltaire's, who employed 

 himself in his garden at Ferney in cutting off the horns and heads of 

 snails, to see whether, or how far, they grew again. 



