84 THE EVOLUTION OF SEX. 



new formation. But some years later, and after having been 

 engaged in observing the phenomena of development in the 

 incubaied egg, he again changed his views, and during the 

 remainder of his life was a keen opponent of the system of 

 epigenesis, and a defender and exponent of the theory of 

 'evolution,' as it was then named." 



The preformation theory found more and more definite 

 expression in the works of Bonnet, Buffon, and others. It is 

 now necessary to sum up its main propositions. 



The germ, whether egg-cell or seed, was believed to be a 

 miniature model of the adult. "Preformed" in all trans- 

 parency lay within the egg the future organs, only requiring to 

 be unfolded. Bonnet affirmed, that before fertilisation there 

 lay within the fowl's ovum an excessively minute but complete 

 chick. They compared the germ to a complex bud, which 

 hides within its hull the floral organs of the future. Harvey 

 had said, "the first concrement of the future body grows, 

 gradually divides, and is distinguished into parts ; not all at 

 once, but some produced after the others, each emerging in its 

 order." Very different was Haller's first and last utterance, 

 " There is no becoming ; no part of the body is made from 

 another, all are created at once." This was obviously a short 

 and easy method with embryology, if the organism was literally 

 preformed in the germ, and its development simply a growth 

 and an unfolding. 



But this was not all. The germ was more than a marvellous 

 bud-like miniature of the adult, it necessarily included in its 

 turn the next generation, and this the next — in short all future 

 generations. Germ within germ, in ever smaller miniature, after 

 the fashion of an infinite juggler's box, was the corollary 

 logically appended to this theory of preformation and unfold- 

 ing, — of evolution^ as it was then called, in a very different but 

 more literal sense from that in which we now use the word. 



A side controversy of the time arose between two schools, 

 who called each other "ovists" and "animalculists." The 

 former maintained that the female germ element was the more 

 important, and only required to be as it were awakened by the 

 male element to begin the process of unfolding. The animal- 

 culists, on the other hand, asserted the claims of the sperm to be 

 the bearer of the miniature nest of organism within organism, 

 and supposed that it only recjuired to be fed l)y the ovum to 

 enlarge and unfold the first of the models which it concealed. 



