THE EXPERIMENTS. 239 



Before leaving this fubjed, upon which I 

 have, perhaps, dwelt too long, I muft ftill add 

 another remark, which may lead to fome ule- 

 ful conclufions. Thefe pretended fpermatic 

 animals, which are nothing but the organic 

 living particles of food, exift, not only in 

 the feminal fluids of both fexes, and in the 

 remnants of food that adhere to the teeth, but 

 likewife in the chyle and in the excrements. 

 Leeuwenhoek, having met with them in the ex- 

 crements of frogs, and of other animals which 

 he difleded, was at firil greatly furprifed ; and, 

 not being able to conjecture from whence ani- 

 mals could proceed fo fmiilar to thofe in the fe- 

 minal liquor he had juft been examining, he 

 accufes his own want of dexterity, and fuppofes, 

 that, in diffeding the animal, he had inadver- 

 tently opened the feminal veffels, and that the 

 femen had in this manner been mixed with the 

 faeces. But, having afterwards obferved the 

 fame phaenomenon in the faeces of other ani- 

 mals, and even in his own, he was then totally 

 nonplufled. It is worthy of remark, that 

 Leeuwenhoek never found animalcules in his 

 own faeces, but when they were liquid. When- 

 ever his ftomach was out of order, and his belly 

 was loofe, the animalcules appeared ; but, when 

 his food was properly concodted, and his faeces 

 were hard, not a fmgle animalcule was to be 

 found, although he diluted the faeces with wa- 

 ^er. Thefe fads fccm pcrfcdly to coincide 



with 



