1887.] ■•- J-'^ [Claypole. 



Organic Variation Indefinite not Definite in Direction — an Outcome of 



Environment. 

 I 



By Prof. E. W. Claypole, B. A., B. Sc. (Lond.), F. 0. S., &c. Akron, 0. 

 (Read before the American Philosophical Society, April 1, 18S7.) 



Introduction. 



Two remarkable utterances liave recently appeared from the pens of 

 two of the most distinguished biologists of the day in defense of a theory 

 of evolution radically unsound and differing, as the writer thinks, from 

 that which is held by the majority of evolutionists. The eminence of the 

 names of these authors is suflBcieut reason to justify a consideration of the 

 view they have advocated. It cannot be supposed that Prof. Asa Gray, 

 of Cambridge, Mass., and Dr. W. B. Carpenter,* of London, would put 

 forward statements all the aspects of which they had not fully considered, 

 and all the legitimate conclusions from which they were not prepared to 

 maintain. Yet both these distinguished writers have enunciated a view 

 of evolution fraught with momentous consequences to biology. So 

 momentous indeed are they that they exclude (if the views in question 

 are well founded) a very large part of the field of investigation now before 

 the biologist from the lawful domain of natural science and relegate it to 

 another department of enquiry. 



The nature and direction of organic variation are subjects which have 

 become prominent during the intellectual ferment excited by the publica- 

 tion of the '"Origin of Species." As a fact variation is admitted by 

 all evolutionists. It is indeed the cardinal fact on which all theories 

 of evolution do and must depend. And both the -writers above men- 

 tioned alike admit its reality and its importance. Both allow' or 

 tacitly assume that there runs through all organic nature a capability of 

 varying from generation to generation — that under the superficial and 

 obvious resemblance existing between parent and offspring therL! lie 

 deeper and less easily discerned distinctions which differentiate the one 

 from the other and accumulate in certain directions from age to age. 

 This capacity, manifesting itself in the fact of variation, when encouraged 

 or repressed by the action of natural or other selection has— so Darwin 

 maintained — resulted in the extinction of old and the production of new 

 species. 



But while agreeing thus far with most evolutionists the two writers in 

 question express views on variation that are remarkable in the following 

 respect. Instead of proceeding on the ground that variation occurs, or 



* These pages were written before science had been deprived of the services of this 

 veteran laborer and leader in biological research by the deplorable accident which 

 caused his death. 



PROC. AMER. PHILOS. SOC. XXIV. 125. O. PRINTED MAY 20, 1887. 



