THE BEGINNINGS OF LIFE. 373 



such a degree of heat has always proved fatal to them. 

 Looking therefore, on the one hand, at the uniformity 

 in the experimental evidence, which has itself extended 

 over a wide basis, and on the other, at the comparative 

 uniformity in fundamental nature and property existing 

 between all the lowest kinds of living things which 

 are almost wholly made up of a more or less naked 

 living matter or protoplasm it is only reasonable for us 

 to conclude, until direct evidence can be adduced to the 

 contrary, that that which holds good for the many 

 without exception, may prove to be a rule of universal 

 application. Therefore it was that the commission 

 appointed by the Societe de Biologic (and M. Pasteur 

 himself for a long time) assumed that none of the lower 

 kind of organisms could survive in a fluid which was 

 raised to a temperature of 2i2F. 



No evidence has as yet been adduced which is capable 

 of shaking the validity of this conclusion, so that the 

 experiments just related afford strong evidence in favour 

 of the view that the organisms found in my experimental 

 fluids were there evolved de novo. Other experiments 

 with negative results, in the face of these, cannot prove 

 the impossibility of such a mode of evolution. And yet 

 the experiments of Schwann and others were deemed by 

 many to have conclusively upset the doctrines of the 

 evolutionists. The particular fluids with which they 

 experimented were only exposed to a temperature of 

 2i2F, but they worked under a set of conditions which 

 are considered by many to be particularly adverse to the 



