SECOND LECTURE. 119 



of different animated beinsrs. The system of the 

 infusory animals, to which some naturalists have 

 had recourse in order to explain the origin of 

 worms in the human body, is essentially contrary 

 to the nature of those animalcules. 



In fine the crystallization of salts, another ar- 

 gument of the partizans of equivocal generation, is, 

 in my estimation, something too gross and insignifi- 

 cant to occupy my time in refuting it. For this inor- 

 ganic production, the concourse of homogeneous par- 

 ticles is indispensable : before this is applied to 

 animals, it ought at least to be sliown how the com- 

 bination of heterogeneous particles can take place. 



( to) The microscopical observations, on whicli 

 the moderns rest their arguments in favour of the 

 equivocal generation of some less perfect living 

 creatures, ought not, in my opinion, to be regarded 

 as certain proofs, because a subsequent examina- 

 tion has proved them to be false. For example, 

 the infusory worms of Bonnet : Considerations sur 

 les corps organises ; Amsterdam, 1762, tome i, j?. 3, 

 and of Wrisbergf Satura ohservationum de am. 

 malculis infusoriis^ ji. 95, strictly compared witli 

 polypes, and which it has been thought are repro- 

 duced like them, have been found of a different 

 sex by Goeze, Bonnet, JJnd an deverer naturfors- 

 cher ah handlung aus der ImeJdologie herausgege- 

 hen, von Goe%e ; Halle, lyy-*'? P' 457, u'ho has ob- 

 served that all the uteri of the females ivere filled 

 with living fetuses* 



