INTRODUCTION 27 



and pressing question, which alone interests us: 

 " How did the earliest organic inhabitants of our 

 earth, the primitive organisms, arise from inorganic 

 compounds? " 



He, therefore, like Weismann, while taking a more 

 sober view as to the nature of the conclusions 

 that Pasteur and other observers were entitled to 

 draw from experiments attended by negative re- 

 sults, also points to the importance of dealing 

 with inorganic materials, if the question of the 

 possible present-day origin of living matter is 

 sought to be established. 



If Pasteur, Tyndall, and others, drew conclu- 

 sions from their experiments wider than were 

 warranted by their premises, they, as well as all 

 other workers at this problem, intermediate be- 

 tween Spallanzani and themselves, at all events 

 firmly stamped with their authority the nature of 

 the experiments by which alone, if ever, the ques- 

 tion of the present-day de novo origin of living 

 units could be settled. Certain materials were to 

 be enclosed in hermetically-sealed vessels, and both 

 were then to be exposed to what existing know- 

 ledge regarded as lethal temperatures. Secure in 

 their belief that this was the means by which the 

 problem was to be solved, many of them, upon 



