FUNGI. 313 



generation arose from nothing more than the deposi- 

 tion of the germs of organisms which were constantly 

 floating in the air. To this conclusion, however, the 

 objection was made, that, if that were the cause, then 

 the air would contain such an enormous number of 

 these germs that it would be a continual fog. But 

 M. Pasteur replied that they are not there in any- 

 thing like the number we might suppose, and that 

 an exaggerated view has been held on that subject ; 

 he showed that the chances of animal or vegetable 

 life appearing in infusions depend entirely on the 

 conditions under which they are exposed. If they 

 are exposed to the ordinary atmosphere around us, 

 why, of course, you may have organisms appearing 

 early. But, on the other hand, if they are exposed 

 to air at a great height, or in some very quiet cellar, 

 you will often not find a single trace of life. So that 

 M. Pasteur arrived at last at the clear and definite 

 result, that all these appearances are like the case of 

 the worms in the piece of meat, which was refuted 

 by Redi, simply germs carried by the air and 

 deposited in the liquids in which they afterwards 

 appear. For my own part, I conceive that, with the 

 particulars of M. Pasteur's experiments before us, 

 we cannot fail to arrive at his conclusions ; and that 

 the doctrine of spontaneous generation has received 

 a final coup de graced* 



