290 M. E. Claparede on the Theory of the 



miscarriages and deformed children. Leeuwenhoeck contented 

 himself with conveying them into the uterus, where they changed 

 their skins like caterpillars and became transformed into men. 

 Lastly, to come to modern times, according to Prevost and 

 Dumas*, the nervous system of the embryo is a product of the 

 zoosperm, whilst the plastic and irritable organs are formed at 

 the expense of the ovum. 



For a long period warm disputes prevailed between the ovists 

 and the spa-matists. The principal representatives of the former 

 were Malpighi, Antoine Vallisneri f, HallerJ and Bonnet §. 

 Their greatest stumbling-block was the part to be assigned to 

 the seminal fluid. Bonnet and Haller imagined that it might 

 constitute the nourishment of the embryo. It is for this reason, 

 according to them, that a mule has long ears, because the semen 

 of his father, the Ass, contains a large quantity of quintessence 

 of ear, &c. They did not trouble themselves with the obstacles 

 which this opinion might throw in the way of the theory of the 

 inclusion of germs. Some even refused to admit that the sper- 

 matozoids were of any importance; like D. Parsons ||, who de- 

 clared it to be ''an extreme nonsense" to believe that those 

 insignificant creatures called spermatic animalcules could con- 

 tribute in any way to propagation. Daubenton and Needham If 

 only regarded them as a product of the decomposition of the 

 semen ; and we owe some gratitude to Bonnet and Gleichen** 

 for having demonstrated by experiment that the seminal fluid of 

 hybrids was incapable of fecundation because it contained no 

 spermatozoids, which however has not prevented Sir Everard 

 Homett in our own century from denying their existence 

 entirely. 



Nevertheless the spermatists appear to have carried the ridi- 

 culous still further than the ovists. As a foretaste we have 

 already given a sketch of Andry^s romances. He attributed the 

 nature of the animals to their spermatozoids ; thus those of the 

 sheep lived in flocks even while still in the testicle and epidi- 

 dymis. Santanelli regarded them as cylindrical spirits with five 

 points. Bat the first spermatist was undoubtedly Aristotle J {, 



* Annales des Sciences Naturelles, ii. 



t Op. cit. sup. 



X Elementa Physiologic Corporis humani. Lausannae, 1757-1/66. 



§ Considerations sur les corps organises. 



II Philosophical Observations on the Analogy between the Propagation 

 of Animals and that of Vegetables. 1762. 



IF Notes des nouvelles recherches sur les decouvertes microscopiques de 

 I'Abbe Spallanzani. Londres, 1769. 



** Abhandl. iiber die Samen- und Infusionsthierchen. 1788. 



tt Lectures on Comparative Anatomy, vol. v. 1828. 



;|;;|; See his works Ilepl Trjs yeveaecos and IIcpi (aniou /xop/coj/. 



