NATURE AND NURTURE 65 



only as an indication of culpable ignorance of history; for the 

 hypothesis has been tried and found wanting, and it was rejected 

 as inadequate more than two thousand years ago. To come down 

 to modern times, Wallace, Darwin, Huxley, and Gray, men who 

 were, assuredly, unprejudiced by opposition to the doctrine of the 

 mutability of species, have all told us that they studied Lamarck 

 with all diligence, and found, in his works on this subject, nothing 

 of value. 



The views of the Neo-Lamarckians, as I understand them, are 

 somewhat broader than those of Lamarck, but fundamentally the 

 same, and, briefly stated, are as follows: The useful changes 

 which are produced in the structure, habits, instincts, and other 

 faculties of living things, through contact with the world around 

 them, are inherited by their children; and this inheritance, aided, 

 it may be, by natural selection, is an efficient factor in the origin of 

 species, and has gradually adjusted, or given material aid in adjust- 

 ing, the characteristics of each organism to its needs. Stated still 

 more briefly, it is the doctrine that organic evolution has been 

 brought about, or at least greatly aided, by the inheritance of 

 nurture. 



We must now dwell upon a point which seems worthy of atten- 

 tion. Lamarck believed that the useful effects of the conditions of 

 life are the ones which are inherited, and this is the only point 

 worth notice; for if these effects may be indifferently useful, use- 

 less, or injurious, they can have no bearing upon the origin of 

 adjustment. In inorganic nature it may be an even chance whether 

 an external change be destructive or preservative, but, when we 

 remember how narrow the range of adjustment of each living being 

 is, the probability that haphazard effects will be injurious or neutral 

 rather than beneficial is prodigious. Even if they are inherited, the 

 effects of nurture cannot cumulate in adaptation except as an acci- 

 dent so improbable that only the most conclusive evidence can 

 prove such an event; unless indeed it can be shown that nurture 

 is beneficial independently of selection. 



While the chances seem all against adaptive modification 

 by the direct action of the conditions of life, I think we may 

 challenge the Lamarckian to show a single species which has 

 been modified to its own disadvantage. There are species which 



