382 DARWINISM TO-DAY. 



has enjoyed little general recognition and almost no em- 

 phasis from supporters of Lamarckism or neo-Lamarckisrru 

 As the great strength of the natural selection explanation of 

 species-change and adaptation lies precisely in the logical 

 nature of its premises and conclusions rather than on scien- 

 tific observation and experiment, 7 it certainly is not unfair 

 to emphasise any similar kind of proof tending to support 

 the Lamarckian type of explanation. 



The logical proof that I refer to is simply this : It is a 



universally admitted fact that environment and functional 



A logical proof stimulation can and do modify organisms dur- 



for the introduc- . ,, . ,. r . , ,, ,, . r r 



tion into phylog- m & their lifetime, and that this modification 



ony of adaptive j s usually plainly adaptive. It is also an 

 ontogenetic . 



changes. admitted fact that species differences or modi- 



fications are often identical with these ontogenetic modifica- 

 tions. That is, that under similar environment or life 

 conditions species modification often follows the same lines 

 as ontogenetic or individual modification. Now when we 

 recall the possibilities of the hosts of ways in which the 

 necessities of adaptation to varying environment might be 

 met by selection among nearly infinite fortuitous variations, 

 and yet see that exactly that means or line or kind of adapt- 

 ive change occurs, which in the case of the individual is 

 plainly and confessedly a direct personal adaptive reaction 

 to varying environment, is it not the logical conclusion that 

 the species change and adaptation is derived, not by the 

 chance appearance of the needed variation, but by the com- 

 pelled or determined appearance of this variation ? In other 

 words when species differences and adaptations are identical 

 with differences and modifications readily directly produci- 

 ble in the individual by varying environment, are we not 

 justified, on the basis of logical deduction, to assume the 

 transmutation of ontogenetic acquirements into phyletic 

 acquirements, even though we are -as yet ignorant of the 

 physico-chemical or vital mechanism capable of effecting the 



