THE GENESIS OF LIFE. 181 



organisms are generated de noi-o from lifeless matter, the 

 advocates of spontaneous generation have alleged that such 

 low animalcules as the Euglence have been seen to become 

 transformed into rotifiers, or " wheel animalcules," a trans- 

 formation not more startling to the naturalist, as remarked 

 by the Rev. W. H. Dallinger, than that whereby a humming- 

 bird could be " hatched from a snake's egg,'' or the fact of 

 " a gorilla being born from a kangaroo." The evidence of 

 this microscopist, and of his fellow-labourers in the field 

 of the minute, is highly interesting, as tending to show that 

 the analogies of nature form, after all, a surer guide towards 

 true conceptions of natural things, than the far-fetched 

 suggestions of experimenters in new and undetermined lines 

 of inquiry. A minute organism one of the monads 

 measuring the jiiooth of an inch in long diameter, was thus 

 found, after nine weeks, in an infusion of cress, which had 

 been hermetically sealed during ebullition, and afterwards 

 exposed to a temperature of 27o-275 F. for at least twenty 

 minutes. The monad thus described and figured is now a 

 well-known organism, its life-history and development having 

 been carefully studied by the microscopicist just mentioned. 

 These monads were found to be killed by an exposure to a 

 temperature of 140 F., and the advocate of spontaneous 

 generation therefore uses this latter fact in support of his 

 contention that the animalcule must have originated spon- 

 taneously, seeing that the fluid in which it appeared had 

 previously been heated up to 275 F. But the monads 

 multiply by means of little spores or germs, and these spores 

 resist a temperature of 300 F. ; this fact endorsing the 

 statement already made, that the germs of these lower 

 organisms can bear an infinitely greater heat than the adults. 

 Consequently, as Mr. Dallinger remarks, "by the logic of 

 facts, the monads were not a result of ' spontaneous genera- 

 tion,' but were the natural outcome of a genetic product 

 (namely, the heat-resisting germs) contained in the infusion, 

 and which the heat employed could not destroy" 



The assertion that lower organisms could be seen giving 



