8o EMBRYOLOGY IN ANTIQUITY [pt. ii 



motion the sinewes be the instrumental! cause, but afterwards they 

 become perfect Hving animall creatures, when being come forth of 

 the wombe, they take in breath from the aire." 



Herophilus described the ovaries and the Fallopian tubes, but did 

 not advance further than Aristotle towards correct sexual physiology 

 in this respect. We gather that he made many dissections of embryos 

 from the testimony of Tertullian, though this may not be worth much. 

 Moreover, he called the outer membrane of the brain, chorion, after 

 the membranes which surround the embryo. He gave a correct de- 

 scription of the umbilical cord, except that he assigned to it four vessels 

 instead of three, carrying blood and breath to the embryo. The 

 veins, he thought, communicated with the venae cavae, and the 

 arteries with the great artery running along the spine. Herophilus 

 also occupied himself much with obstetrical matters, and wrote a 

 treatise on them, fiaicoTtKov. Together with Erasistratus he denied 

 that there were any diseases special to women other than those 

 attendant on their special sexual functions, but the greatest contribu- 

 tion which he made to biology was the association of the brain with 

 the intellect^, for even Aristotle had made the he^rt the seat of the 

 mental individual. 



Erasistratus did not study embryology as much as did Herophilus, 

 but a passage in Galen throws an interesting light on his notions of 

 embryonic growth. "The heart", says Galen, "is no larger at first 

 than a millet seed, or, if you like, a bean. Ask yourself how it could 

 grow large otherwise than by being distended and receiving nutri- 

 ment throughout its whole extent, just as we have shown above that 

 the seed is nourished. But even this is unknown to Erasistratus, who 

 makes so much of Nature's Art. He supposes that animals grow just 

 like a sieve, a rope, a bag, or a basket, each of which grows by the 

 addition to it of materials similar to those out of which it began to 

 be made." This is only one instance out of many in which Galen, the 

 teleologist, finds fault with Erasistratus, the mechanistic philosopher. 



During the period when the biological school of Alexandria was 

 at its height, that city became an important Jewish centre. Two 

 centuries later it was to produce Philo, but now the Alexandrian 

 Jews were writing that part of the modern Bible known as the Wisdom 

 Literature. In books such as the Wisdom of Solomon, Ecclesiasticus, 

 Proverbs, etc., the typical Hellenic exclusion of the action of gods 



^ This was not absolutely new: Alcmaeon had held the same view (see Burnet). 



