50 CALIFORNIA ACADEMY OF SCIENCES. 



ferently explained. And it seems to me that some 

 fairly well established, if not absolutely convincing, 

 cases have been adduced. Furthermore, the Neo-Dar- 

 winians maintain the illogical assumption that the 

 changes which are observed in the individual have no 

 possible causal connection with the changes which take 

 place in the race, this assumption being contradictory 

 to the law of correspondence of the ontogenic and phylo- 

 genic series. Lastly, it is impossible to explain, from 

 the Neo-Darwinian point of view", simultaneous varia- 

 tions of an adaptive nature. 



From all this we may come to a provisional conclu- 

 sion that acquired characters are transmissible. We 

 are justified in using this assumption as a working 

 hypothesis, and in feeling confident that future investi- 

 gation will place it upon a footing where it is beyond 

 the possibility of refutation. 



VARIATION AND NATURAL SELECTION. 



The end of science is the establishment of natural 

 law, which is merely the orderly relationship existing 

 between phenomena, and consequently cannot be con- 

 sidered as an ultimate cause. Thus gravitation is merely 

 a name for the observed relation between bodies, but 

 does not in any way tell us why these relations exist. 

 Evolution is a term expressive of change in form, and 

 modern biology is striving to determine the precise laws 

 conditioning such changes as occur in organic beings. 

 There are two sets of changes — ontogenic and phy- 

 logenic. It has become the fashion of late years 

 among certain scientists to attribute changes of the 

 second class solely to the action of natural selection, 

 and it thus becomes necessary in inquiring into the 

 laws of evolution to consider first this principle, and de- 

 termine what it can effect. 



