52 EVOLUTION 



the presence of a life-giving agency in the primitive earth 

 that has almost disappeared in our time. Physicists 

 suspect that there are large quantities of radium in the 

 sun to-day, and our earth would have a proportionate 

 abundance in its Incandescent stage. The question of 

 the origin of life has long been obscured by Pasteur's 

 supposed demonstration that there is no such thing as 

 " spontaneous generation." All that Pasteur did was to 

 short that the specific cases of "spontaneous generation" 

 submitted to him were not genuine; and it must be 

 added that Dr. Bastian has seriously challenged the 

 value of his demonstration, and believes he has found 

 cases of the rise of organisms (such as Bacteria) without 

 living parents.* At all events the utmost Pasteur may 

 be held to show is that living things are not formed 

 to-day without living parents, or that no such case is 

 known to us. There are, however, distinguished biolo- 

 gists, like Professor Naegeli, who hold the contrary; and 

 even Professor J. A. Thomson thinks that protoplasm 

 may be forming daily in nature in minute quantities. 



The chief thing to remember is that, whatever 

 happens to-day, the condition of the earth was radically 

 different at the beginning of geological time. The 

 matter of which it is composed had at one time a 

 temperature that we cannot reproduce to-day, and radio- 

 activity and electricity were intensely active. Here we 

 have possibilities of combinations of matter and energy 

 that greatly favour the view that life was first produced 

 under natural conditions which have passed away for 

 ever. Some physiologists, like Verworn and Preyer, 

 believe that the essentially active and obscure principle 

 of living matter is a radicle of cyanogen, a compound of 



* See his Nature and Origin of Living Matter (1905) and 

 Evolution of Life (1907). 



