GENERATION' OF ANIMALS 



the early scientists and philosophers and to other 

 works of reference." Alcmeon, to whom also he 

 refers, is an important figure, since it was he, ap- 

 parently, who originated the famous doctrine of 

 " passages " (or " pores," iropoi) in connexion with 

 sensation, and held that the brain was the common 

 sensorium, in which belief he was followed by Hippo- 

 crates and Plato, whereas Empedocles and Aristotle 

 reverted to the older view that the heart is the central 

 organ of sensation. Alcmeon also treated systematic- 

 ally of the special senses, in particular that of sight. 

 Other theories of his mentioned by Aristotle mav be 

 found by reference to the Index. 



Anaxagoras of Clazomenae, the last great name in 

 the Ionian philosophic succession of Asia Minor, is 

 well known for his theory that voi«s is responsible for 

 the order of the universe as a whole, just as it is for the 

 order which is to be discerned in li\'ing creatures, 

 and for his remarkable theory of matter, which he 

 constructed specially \\'ith a \'iew to accounting for 

 generation and gro^^'th. I have treated fully of this 

 elsewhere.'' 



Empedocles of Acragas, a striking figure, was a 

 slightly younger contemporary of Anaxagoras, and 

 was reno^^Tied as a politician, religious teacher, 

 rhetorician, philosopher, and physician : he was the 



" e.g., J. Burnet, Early Greek Philosophy ; see also for 

 Hippocrates, W. H. S. Jones (Loeb ed.) ; for Alcmeon, 

 J. Wachtler, De Alcmaeone Crotoniata (1896) ; and M. 

 Wellmann, Die Schrift it. Iprjs vovaov, in Archiv f. Gesch. der 

 Med. XXII (1929), 290-31:?. For a conspectus of ancient 

 embryology, H. Balss, Die Zeugungslehre u. Embryologie in 

 der Antike, in Quellen u. Studien zttr Gesch, der Naturvc. 

 u. der Med. V (1936), 193-374. 



» C.Q. XXV (1931), 27 ff., 112 IF.; see also O.A. 723 a 7. 



