2o8 COMPARISON OF 



* particulae, paitim longiores partlin breviores ; 



* fed altera fui extremitate craffiunculae ; iftas 

 ' particulas in animalcula tranfituras efle non du- 



* bitabam.' From this paflage, it is apparent that 

 Leeuwenhoek had feen in this feminal Hquor, 

 ■what I have found in the femen of all the ani- 

 mals which I examined, moving bodies that differ- 

 ed in fize, figure, and motion ; and thefe cir- 

 cumftances, it is obvious, correfpond better with 

 the notion of organic particles in motion, than 

 with that of real animals. 



It appears, therefore, that Leeuwenhoek's ob- 

 fervations, though he draws very different con- 

 clufions from them, perfedly correfpond with 

 mine : And, though there be fome oppofition in 

 the fads, I am fully perfuaded, that, whoever 

 lliall take the trouble of repeating the experiments, 

 will eafily difcover the fource of thefe diffe- 

 rences, and find that I have related nothing but 

 truth. To enable the reader to decide in this 

 matter, I fliall add a few remarks. 



We do not always fee, in the human femen, 

 the filaments I have mentioned : For this pur- 

 pofe, the liquor muft be examined the moment 

 it is extracted from the body ; and even then 

 they do not uniformly appear. When the li- 

 quor is too thick, it prefents nothing but large 

 globules, which may be diftinguifhed with a 

 common lens. When examined with the mi- 

 crofcope they have the appearance of fmall oran- 

 ges ; they are very opaque, and one of them oc- 

 cupies 



