THE BEGINNINGS OF LIFE. 431 



take place in plants during every moment of their 

 growth even though such chemical combinations oc- 

 cur c spontaneously,' or independently of the influence 

 of any pre-existing living protoplasm. 



It may be easily understood., however, that he who 

 investigates this subject has to work under the in- 

 fluence of a set of conditions which are of the most 

 unfavourable description. What he wishes to ascer- 

 tain is whether in the wide field of nature in its 

 ponds, its lakes, its rivers, and its ocean beds, where 

 there is the freest play of cosmical forces upon the 

 most suitable materials any de novo origination of living 

 matter is taking place. And with the view of answering 

 this portentous question, he is compelled (if. he would 

 avail himself of experimental conditions which shall 

 be free from all chances of error) to resort to a poverty 

 of conditions, which seems but a mockery of the wealth 

 of nature. In the one case we have ponds, containing 

 in solution an abundance of protein materials whose 

 virtues have not been impaired by the blighting in- 

 fluence of heat, and which are freely exposed to air, 

 light, and all those other known or unknown cosmical 

 agencies which stimulate the growth of living matter. 

 Whilst, in the other case, the experimenter has to 

 content himself with boiled organic infusions, shut 

 up within the narrow confines of a small, hermetically- 

 sealed flask. Seeing, however, that conclusive results 

 are still obtainable in spite of these unpromising con- 

 ditions, the subject is one on which science may be 



