236 THE NATURE AND ORIGIN OF LIFE 



at the moment of fecundation and introduces into the series 

 of hereditary patrimonies an inevitable discontinuity. 

 The only thing open to dispute relatively to a lineage pro- 

 pagated by sexual generation is not the continuity or dis- 

 continuity of its variations a question without meaning- 

 hut the importance of the discontinuities produced at each 

 generation. 



Mutations 



For some years great noise has been made about a dis- 

 covery of De Vries which, according to many authors, would 

 bring into question all Transformism. According to it, 

 there would be a sudden appearance of new species. In- 

 stead of verifying that patient adaptation which Lamarck 

 placed in the foremost rank of modes of variation, we 

 should see appear from time to time, without known reason, 

 new species capable henceforth of reproducing themselves 

 indefinitely and differing by very clear-cut characters 

 from the parent species whence they are derived. 



In a bed of several thousand Oenothera plants there 

 are found, for example, three or four individuals differing 

 notably enough from the primitive species to merit a new 

 denomination ; and these individuals, kept apart, repro- 

 duce themselves in their own likeness. Here then, say the 

 Neo-Darwinians, we have a new species obtained per saltum 

 by sudden variation or mutation. It is well to reflect a 

 little before we accept, on the faith of such observation, 

 that all new species have thus appeared suddenly and by 

 chance. 



In the first place, what is a species ? By what do we 

 recognize that we have the right to call new species these 

 aberrant types of Oenothera which chance to exist among 

 the thousands of plants sowed by De Vries ? We shall 



