278 



and thereby added one more to six pre\'ious instances which prove 

 that these lowest of all organisms arise, not in that which is not 

 li^'ing, but, like all other living things, in that which has been 

 vital. 



' * A further instance was brought forward to point out diversity 

 and assist in generalization ; and from the whole the reverend 

 gentleman strongly maintained that even among these apparently 

 structureless beings there was no caprice, their life-circles were 

 as regularly circumscribed as those of a buttei'fly or a wasp. In 

 shorty the only forces seen in operation were those formulated in 

 the great Darwinian law of the Origin of Species. 



*' Mr. Dallingcr further pointed out the importance of knowing 

 whether the spores or ova of the septic organisms could resist 

 heat more successfully than the adult forms ; for if they could, 

 the heat which destroyed the matured organism in a putrefactive 

 fluid would not necessarily prevent their re-appearance. 



'' The result of a large series of careful experiments proved that 

 the spore of the organism he had previously described could re- 

 sist a temperature of 250° Fahr. dry heat, and by the use of a 

 very delicate apparatus it was proved that the limit of endurance 

 of the spore in a fluid was 220° Fuhr., and consequently it would 

 take 30° at least more heat to destroy the spores in the dry state 

 than in a heated fluid. 



' ' With three other septic organisms there was found to be re- 

 spectively 38°, 32°, and 28'' of dilference between the two me- 

 thods of heating the germs. 



''As the adult forms were destroyed by temperatures varpng 

 from 140° to 142° Fahr. tlie destruction of the organism is not 

 that of its germs, and therefore to infer that the presence of an 

 organism in a fluid after its exposure to a heat known to be de- 

 structive to the adult is determined by '' spontaneous generation " 

 is simply begging the question ; and in a speuiflc instance in 

 which Dr. IJastian had made such an inference, Mr. Dallinger 

 showed that the germs of the form in question had not been 

 destroyed by the heat used, and therefore it had naturally re- 

 appeared. 



