THE BEGINNINGS OF LIFE. 471 



Living organisms have, undoubtedly, been obtained 

 from hermetically sealed flasks which had been heated 

 for various periods to such temperatures; and many 

 persons have been not a little surprised at the com- 

 paratively high forms of life which have presented 

 themselves. This of itself has been deemed by some 

 to be a difficulty of so serious a nature as to make 

 them hesitate to accept the results of the experiments 

 principally on account of a preconceived notion that 

 such organisms could not arise de novo and without 

 ordinary parentage. Although willing to concede that 

 the very simplest organisms might so arise, they are 

 quite indisposed to believe that some of the higher 

 forms which I have represented could have had an 

 independent origin. I will not, however, at present 

 enter upon this question, but will merely state that 

 such difficulties are likely to disappear on a more 

 thorough consideration of the subject as it is hoped 

 the reader will perceive after a perusal of Chaps, xiii. 

 xiv. and xv. 



Limiting ourselves at present to the fact that specks 

 of living matter must either have been born in the 

 experimental fluids after they had been exposed to 

 the heat, or else (having pre-existed in the fluids) have 

 braved its influence, we have merely again to consider 

 which of these alternatives is the more probable. A 

 choice must be made, and yet, as Prof. Wyman has 

 pointed out, it does not appear at first sight that a 

 profitable resort can be made to arguments from analogy. 



