52 EMBRYOLOGY IN ANTIQUITY [pt. ii 



Anaxagoras of Clazomenae (500-428 B.C.) may have said that the 

 milk of mammals corresponded to the white of the fowl's egg, but 

 that observation is also attributed to Alcmaeon of Croton. It is more 

 certain that he spoke of a fire inside the embryo which set the parts 

 in order as it developed, and that the head was the part to be formed 

 first in development. This thesis was supported by Alcmaeon, and 

 by Hippon of Samos, a Pythagorean, in the fifth century B.C., but 

 Diogenes of Apollonia maintained about the same time that a mass 

 of flesh was formed first, and afterwards the bones and nerves were 

 differentiated. Plutarch remarks about this: "Alcmaeon affirmeth 

 that the head is first made as being the seat of reason. Physicians 

 will have the heart to be the first, wherein the veines and arteries are. 

 Some thinke the great toe is framed first, others the navill". 



The other contributions of Diogenes to this primitive embryology, 

 were the view that the placenta is the organ of foetal nutrition, and 

 the view that the male embryo was formed in four months but the 

 female embryo not till five months had elapsed — a notion also found 

 in Asclepiades and Empedocles, as we have seen. He also associated 

 heat with the generation of little animals out of slime, and compared 

 this with the heat of the uterus. He agreed with Empedocles that 

 the embryo was not alive. "Diogenes saith that infants are bred within 

 the matrice inanimate, howbeit in heat, whereupon it commeth that 

 naturall heat, so soon as ever the infant is turned out of the mother's 

 wombe, is drawen into the lungs." But the principal pre-Socratic 

 embryologist was, as Zeller points out, Alcmaeon of Croton, who 

 lived in the sixth century B.C., a disciple of Pythagoras, though ap- 

 parently an independent one. He is said to have been the first man 

 to make dissections. The fragments of Alcmaeon (who is not to be 

 confused with Alcman, the Lacedaemonian poet) have been col- 

 lected together by Wachtler; the most important are xviii and xix. 

 Athenaeus in the Deipnosophists says, in his usual chatty way, "Now 

 with respect to eggs Anaxagoras in his book on natural philosophy 

 says that what is called the milk of the bird is the white which is in 

 the eggs". This may be a wrong ascription; it may refer to Alcmaeon, 

 for Aristotle says in his book on the generation of animals, "Nature 

 not only places the material of the creature in the egg but also the 

 nourishment sufficient for its growth, for since the mother-bird cannot 

 protect the young within herself she produces the nourishment in the 

 egg along with it. Whereas the nourishment which is called milk 



