Fecundation of the Ovum. 2U1 



who declares that the actual procreaut element is the male, 

 whilst the female eleuient only furnishes nourishment. Tiie 

 ovists, as well as many spermatists, were partisans of the theory 

 of the preformation or evolution of germs, a theory which soon 

 gave place to that of metamorphosis. Bonnet himself appears 

 to have had a tendency this way, for he puts forward the idea, 

 that the air, the water, the earth and every solid body, are 

 magazines containing germs. The same germs, which, passing 

 into plants produce buds and Howers, give birth to embryos 

 when they penetrate into the ovaries of animals *. In reality 

 this is not far from the opinion of Ileraclitus, who maintained 

 that the germs were diffused everywhere, and that they were 

 developed as soon as they arrived in the proper sexual organs. 

 Perrault, Needham, Jiuffon and Treviranus merely worked out 

 this kind of panspermism in various directions, until Okcnf 

 imagined that these universally diffused germs were to be found 

 in the Infusoria. 



It must be confessed that the imagination of our forefathers 

 was very prolific in the fabrication of theories of generation 

 which often approached pretty closely to the ridiculous, or at all 

 events to the comic. However, all these beautiful edifices 

 crumbled one after the other by their own weight, and of late 

 years there appeared to be a tacit agreement between phj'sio- 

 logists, by which they engaged to steer clear of this subject until 

 they had facts before them. But in the absence of facts, it was 

 necessary to rest contented with the general ignorance, which 

 however was soon veiled in a tinsel cloak, by having recourse to 

 a force, that dens ex machind which physicists, chemists, phy- 

 siologists and other philosophers use and abuse in accounting 

 for that which tbcy cannot explain. 



People accordingly admitted a dynamic action of the zoo- 

 sperm. This arrived at the ovum, without however penetrating 

 into its interior, as Andry's little door did not exist ; and by its 

 simple presence, in virtue of a force belonging to its predicate 

 of spermatozoid, fecundation was effected, but no one knew very 

 well how or why. The embryologist Bischoff was one of the 

 principal defenders of this dynamism, which, indeed, was nothing 



* The author here appears to have mistaken Bonnet's meaning in some 

 imaeeouiitable manner ; his statements seem to have a directly opposite 

 tendency. Thus in stating his hypothesis of the universal diffusion of 

 germs he says, *' they only become developed when they meet with suitable 

 matrices, or bodies of the same nature ;" and in a subsequent })assage he 

 adds, " it is only the germs which contain organic wholes, of the same 

 kind as that into which thev are introduced, that are developed there." — 

 W. S. D. 



t Die Zengung. B.amberg, 1805. 



19* 



