No. 627] 



ADAPTATION 



363 



Taking heart from this skepticism among the biolo- 

 gists themselves, reactionaries are boldly coming for- 

 ward with the assertion that the evolution principle has 

 been discredited. It is certain that the spread of such 

 ideas is not calculated to further the advancement of 

 knowledge. Lack of an adequate hypothesis is not dis- 

 proof of any possible hypothesis. 



Moreover, it would now seem that some of tliese ad- 

 missions of inadequacy have been premature. Much of 

 the recent abandonment of the natural selection theory 

 has been due to neo-Mendelian dogmatism. Selection, it 

 is claimed, can only separate strains having different 

 mean characters. It can not change the moan characters 

 of a pure strain. But the experiments of Castle and 

 some other breeders may be cited as evidence that such 

 a contention is far from being established. And even 

 those who reject Castle's interpretation of these results 

 have been forced to concede that in some cases selection 

 may bring about the indefinite modification of our stock 

 —call the process sorting" if we will. 



So, too, the Lamaix'kiati ])rineipl(' occuj)ies the curious 

 position of being douinal icall\ (Icuicd or wliollx- ignored 

 by a large and iiiHuciitial class of writers, at tlir same 

 time that others arc al)lc to adduce appa I'cnt ly coiiviue- 



ai-ra\- of i 11. li I'cct oi' ci rcuiiist ant ial c\ idciicc for this prin- 

 ciple (lrri\C(l troiii an in>p(H-iion of the actual products 

 of cvolulion as \V(> lind tliciu. And we have a certain 

 aiiiount ol direct, cxperiniejital evidence wliicli can not 

 l)e thrown aside as irrelevant or uiitrust wort h\-. While, 



inn factoi' are doubtless i)rcniaturc, the douniatic denial 

 ot thi. factor Nerx nearl> aniount^^ to .ell Multiricatioii. 



Thu^. if we n.a> rea.l the .iun. ol the tinu-., the two 

 chief naturalistic explanation, ot exolution nia\ survive 



tant part in our interpretation of life. i'>y tins. I (h* not 

 wish to be understood as aruuin-- that either oi' both of 

 these theories constitute an ade<iuate exphuiation (even 



