J)?2 ANIMALCULA OF INFUSIONS. I*" 



evidence of their originating from a pre-organifed 

 principle, fmce it has never been difcovered by 

 me ; but, adhering to eftablifhed facts, this opi- 

 liion is to be embraced : for, if the polypi, firft 

 feen in infufions, are not produced by plaftic ot 

 vegetative powers, which fo many facts have 

 proved chimerical, and cannot be the fame that 

 fall from the air into the infufion, it is moft ra- 

 tional to infer, that they proceed from fome 

 germ, or pre-organifed principle, whatever it may 

 be called. It is of no importance whether the 

 germ or feminal principle is invifible, or reproduc- 

 tion of the polypi eifefled by means of divifion 5 

 becaufe, with refped to the firft, we know that 

 we ought not always to conclude on the non-ex- 

 iftence of a thing which we do not perceive ; and 

 in the cafe before us, the germs may be either too 

 tranfparent or too minute to fall under our fenfes 5 

 and with refpedt to the fecond, this is not the on- 

 ly polypus which multiplies by germ.s or eggs, 

 as fome others do the fame. 



I have fuppofed that the germs whence animal- 

 cula originate come from the air j and this ap- 

 pears moft reafonable from the fupport of un- 

 doubted fa£ls, which I fhall briefly enumerate ( i ), 



Sixteen 



( 1 ) Mulkr alfo thinks it probable that aEimalcula and 

 their eggs come from the air. Praefat. p. 22, 297, 298, 



