54 EMBRYOLOGY IN ANTIQUITY [pt. ii 



physician than any of his predecessors, if we may except the legendary 

 names of Aesculapius, Machaon and Podalirius. It has not been 

 believed for many centuries past that all the writings in the collection 

 of Hippocratic books were actually set down by him, and much 

 discussion has taken place about the authenticity of individual 

 documents. 



Most of the embryological information is contained in a section 

 which in other respects (style, etc.) shows homogeneity. We are there- 

 fore rather interested in that unknown biological thinker who wrote 

 the books in this class, for he could with considerable justice be 

 referred to as the first embryologist. Littre discusses his identity, 

 but there is no good evidence for any of the theories about it, though 

 perhaps the most likely one is that he was Polybus, the son-in-law of 

 Hippocrates. That the writings on generation are only slightly later 

 than the time of Hippocrates is more or less clear from the fact that 

 Bacchius knew of them, and actually mentions them. 



For the most part the embryological knowledge of Hippocrates is 

 concerned with obstetrical and gynaecological problems. Thus in the 

 Aphorisms, d(f)opicr/iioi, the books on epidemics, eirchrifxiai, the treatise 

 on the nature of women, irepl rywaLKelr)'? (f)V(rio'?, the discussions of pre- 

 mature birth, Trepl eirraixrjvov, the books on the diseases of women, 

 irepl 'yvvaixeiaiv, and the pamphlet on superfoetation, there are many 

 facts recorded about the embryo, but all with obstetrical reference. 

 There are some curious notions to be found there, such as the asso- 

 ciation of right and left breasts with twin embryos and a prognostic 

 dependent on this. 



But the three books which are most important in the history of 

 embryology are the treatise on Regimen, irepl StaLTr}<;, the work on 

 generation, irepl jovr]<;, and the book about the nature of the infant, 

 Trepl ^vaio<; TraiZiov. The two latter really form one continuous 

 discussion, and it is not at all clear how they came to be split up 

 into separate books. In the Regimen the writer expounds his funda- 

 mental physiological ideas, involving the two main constituents of all 

 natural bodies, fire and water. Each of these is made up of three 

 primary natures, only separable in thought and never found isolated, 

 heat, dryness and moisture, and each of them has the power of 

 attracting, eXKeiv, their like, an important feature of the system. Life 

 consists in moisture being dried up by fire and fire being wetted by 

 moisture alternately, rpo^-i'i, the nourishment (moisture) coming into 



