50 HERBERT ALBERT RATNER 



ordered one after the other, and that there first exists a genital 

 particle, by the power of which as from a principle, all the other 

 parts proceed (Exercise 51) . 



Curiously enough, however, the preformationist theory came 

 into prominence again — curiously, because it did so just follow- 

 ing the discovery of the microscope and the aberrations that 

 passed for facts that resulted thereof. But the epigenetic theory 

 has since been restored and given great richness of detail in 

 support. 



It can be seen that Harvey in following Aristotle reaffirmed a 

 truth that was lost during the late Renaissance, but redis- 

 covered in modem times. That it was one of Harvey's prime 

 objects in writing The Generation of Animals to defend and 

 establish the opinion already held by Aristotle has been ex- 

 pressed by Thomas H. Huxley.^ 



15 



REFERENCES TO ARISTOTLE 



In The Motion of the Heart and Blood, which is more a 

 demonstrative work than a descriptive one, 22 references to 

 Aristotle are made. In only one instance does Harvey clearly 

 disagree with Aristotle. In this instance Harvey writes, 

 " Hence, since the veins are the conduits and vessels that 

 transport the blood, they are of two kinds, the vasa and the 

 aorta; and this not by reason of sides (as in Aristotle) , but 

 office (officio) , and not, as is commonly said, by constitution, 

 for in many animals, as I have said, the vein does not differ 

 from the artery in the thickness of its tunic, but is distinct by 

 duties (munere) and use (usu) ." ^® It should be noted that 

 the disagreement is not based on Aristotle's anatomical obser- 

 vations, which D'Arcy W. Thompson states to be " remarkable 



^^ Thomas H. Huxley, " Evolution in Biology," in Darwiniana Essays (New 

 York, 1898), p. 193. 



^^ Harvey, Works, ed. cit., cli. 8, p. 47. The English translations of Harvey 

 appearing in this article are mostly adapted from the Willis translation following 

 consultation with the original Latin. Where possible key Latin terms which have 

 English equivalents are substituted. The Latin text consulted is the edition of 

 Bernardus Albinus (Johannes van Kercjhem, 1737) . 



