The Conditions of Life and Death. 99 



biogenesis, that life arises from pre-existing life, was 

 thoroughly established. At the same time, he expressed 

 his opinion that if he could have been a witness The Fact of 

 of the beginning of organic evolution he would Biogenesis, 

 have seen the origin of protoplasm from not-living mat- 

 ter. The point is clear; on the one hand, the biologist 

 makes the negative statement that so far as he is aware 

 no form of life has ever been observed to arise except 

 from a parent form of the same kind; on the other hand, 

 he suggests the limitation that there may have been, or 

 may still be, conditions in which not-living matter ac- 

 quired the potentialities which we call life. 



The conclusion, then, which most modern biologists 

 accept is, that while there is no known evidence of not- 

 living matter giving origin to living organisms, this does 

 not necessarily exclude (a) the possibility that this once 

 took place, (b) the possibility that it is taking place now, 

 or (c) the possibility that it may be made to take place 

 again. If any of these possibilities should express reali- 

 ties, then our estimate of the potentialities of not-living 

 matter must be heightened. It should perhaps be 

 noticed, as a sagacious friend has pointed out to me, 

 that protoplasm or living matter may still be forming 

 "in extremely small quantities, too small to be visible, 

 and of simple or no structure, but yet sufficiently com- 

 plex in composition to serve as food for organisms". It 

 goes without saying, however, that possibilities do not 

 enter into the solid framework of science. 



Since our data are practically nil, the scientific atti- 

 tude in regard to the problem of the origin of life must 

 be agnostic. Yet many opinions on the sub- 

 ject have been ventured, and some of them S P orig?n of 

 are both interesting and stimulating. Earth p n the 



Quite different from the others is that of 

 Alfred Russel Wallace, who postulates a spiritual influx 

 at the origin of life and in connection with some other 

 great events of history. 



In 1865 and afterwards H. E. Richter expounded his 

 hypothesis that living germs might be eternal, omne 

 vivum ab &ternitate e cellula, and that they might drift 

 through space from sphere to sphere, lodging and de- 



