2o8 EMBRYOLOGY IN THE SEVENTEENTH [pt. ii 



but as destitute of every vestige of probability. As both the vermicular 

 and ovular systems suppose such a progression, they should be ex- 

 cluded for ever from philosophy". He completely destroys the theory 

 which the ovists and animalculists had set up in order to explain 

 resemblance to parents, namely, that, although the foetus might 

 originate either from egg or spermatic animalcule originally, it was 

 moulded into the form of its parents by the influence of the maternal 

 organism during pregnancy. This field, which was more than once 

 disturbed by the contestants during the course of the century, re- 

 ceived systematic attention from time to time by medical writers. 

 There was a memorable dispute on this point between Turner and 

 Blondel, whose polemics, written in an exceedingly witty manner, 

 are still very pleasant and amusing to read. Blondel was the sceptic 

 and Turner the defender of the numerous extraordinary stories which 

 passed for evidence on this subject. It is interesting to note that 

 Turner believed in the continuity of foetal and maternal blood-vessels. 

 Krause and Ens later supported the opinions of Turner, while Okes, 

 in a Cambridge disputation, argued against them. 



Buflfon's sixth chapter, in which he relates the progress of his own 

 experiments, is unfortunate, in that his main result was to discover 

 spermatozoa in the liquor folliculi of ovaries of female animals. The 

 explanation of how he came to make such an enormous mistake 

 has never been satisfactorily given, and it was not long before the 

 truth of the observation was questioned by Ledermuller. It led him 

 naturally to the assertion that the ovaries of mammalia were not egg- 

 producing organs but animalcule-producing organs, and to the view 

 that the beginning of embryonic development lay in the fusion of the 

 male with the female spermatic animalcules — a curious revival of 

 Epicureanism. But it is to be observed that he does not mean one 

 male animalcule with one female animalcule, but rather all with all, 

 in a kind of pangenesis. "All the organic particles", he says, "which 

 were detached from the head of the animal will arrange themselves 

 in a similar order in the head of the foetus. Those which proceeded 

 from the backbone will dispose themselves in an order corresponding 

 to the structure and position of the vertebrae". And so on for all 

 the organs. The fact that for the organs common to both sexes a 

 double set of animalcules will thus be provided does not give Buffon 

 any difficulty and is fully admitted by him. Accordingly he could 

 only agree to the aphorism omne vivum ex ovo in the sense of 



