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THE AMERICAN NATURALIST [Vol. L 



a novel one. But the two groups of phenomena, and the proc- 

 esses involved in each, are still very frequently confounded in 

 other domains than that of use inheritance. The whole eugenics 

 movement, for instance, so far as it is a constructive program 

 and not a mere matter of ordinary practical prophylactic social 

 hygiene, rests upon the assumption that social progress can best 

 be accomplished by organic means. 'It may be rash to deny 

 wholly that such an end can be achieved in this way or that it 

 would be useful. But the orthodox eugenist, from the time of 

 the founder Galton, has consistently and complacently made this 

 assumption without any inquiry as to its justification. Lamarck 

 erected a false doctrine of evolution through explaining the 

 organic in terms of the social, or in terms derived by mere an- 

 alogy from the social. The eugenists of to-day, it may fairly be 

 suggested, bid fair to vitiate a movement that springs from the 

 most sincere of motives, by resting its basis on an interpretation 

 of the social as merely organic. 



In summary, the doctrine of the hereditary transmission of 

 acquired characters is no more disprovable than it is provable by 

 accumulation and analysis of evidence. It springs from a naive, 

 unscientific, and even primitive method of reasoning by analogy, 

 which in this case works to a confusion of the long-distinguished 

 and necessarily distinct concepts of the organic and the social. 

 The doctrine must therefore be dismissed on purely methodolog- 

 ical grounds. It is possible that when the missing factor or ele- 

 ment of evolution is discovered that neither Darwin nor the 

 mutationists have been able to find, this factor will prove to be 

 something superficially similar to use inheritance. But it will 

 differ from the present only half-discredited but discreditable 

 factor of heredity by acquirement, in containing an organic 

 mechanism, and will therefore be essentially different from this 

 crude and confused assumption. 



A. L. Kroeber. 



TRIFOLIUM PRATENSE QUINQUE FOLIUM 



Hugo De Vries in his mutation theory tells us in detail about 

 his production, by means of selection from two mutant forms, 

 of a five-leaved race of red clover. This race he called Trifolium 

 pratense quinquefolium. The two plants obtained for starting 



