THE BEGINNINGS OF LIFE. 333 



such invisible particles possess no higher power of 

 resisting the destructive influence of heat than the 

 parent Bacteria themselves possess a result which is 

 by no means surprising when we consider that these 

 gemmules, however minute, could only be portions of a 

 similar homogeneous living matter, and ought therefore 

 to be endowed with like properties. 



The results just recorded seem all the more trust- 

 worthy also, because they are confirmed by the ex- 

 periments of M. Pouchet 1 , myself, and others, upon 

 the degree of c vital resistance 3 to heat manifested by 

 rather higher organisms, which, on account of their 

 very much greater size and other peculiarities, easily 

 enable the microscopist to decide whether they are 

 living or dead. My observations accord very closely 

 with those of M. Pouchet ; and I have found that an 

 exposure to a temperature of i3iF for five minutes 

 always suffices to destroy all reliable signs of life in 

 Amoebae, Monads, Chlamydomonads, Euglense, Desmids, 

 Vorticellse, and all other Ciliated Infusoria which were 

 observed, as well as in free Nematoids, Rotifers, and 

 other organisms contained in the fluids which had been 

 heated 2 . 



1 'Nouvelles Experiences,' &c. 1864, p. 38. 



2 In opposition to all this concurrent testimony as to the influence 

 of comparatively low temperatures upon the lower forms of life, Mr. 

 Samuelson (Quarterly Journal of Science, Oct. 1870, p. .190) desires to 

 impress us with the idea that they are capable of resisting a very high 

 degree of heat. The evidence which he adduces, however, is quite 

 inadequate to establish the truth of such a conclusion. Having heated 



