324 READINGS IN EVOLUTION, GENETICS, AND EUGENICS 



crop of variations at present supplied; there is no reason to believe 

 that it was less abundant in the past. 



Misunderstanding II. Interpretations are not facts. There are 

 many adaptive characters in plants and animals which may be super- 

 ficially interpreted as due to the direct result of use and disuse or 

 of environmental influence. The Lamarckians have so interpreted 

 them, and the Lamarckian way of looking at adaptations has become 

 habitual to many uncritical minds. They see on modern flowers the 

 footprints of insects which have visited them for untold ages; they 

 speak of the dwindling of the whale's hind-limbs through disuse, of the 

 hardening of the ancestral horses' hoofs as they left the marshes and 

 ran on harder ground; they picture the giraffe by persistent effort 

 lengthening out its neck a few millimetres every century, as the acacia 

 raised its leaves higher and higher off the ground; and they say that 

 animate nature is so full of evidences of the inheritance of acquired 

 characters that no further argument is needed. 



But all this is a begging of the question. It is easy to find struc- 

 tural features which may be interpreted as entailed acquired characters, 

 if acquired characters can be entailed. Obviously, however, we must 

 deal with what we can prove to be modifications, or with what we can 

 plausibly regard as modifications because we find their analogues in 

 actual process of being effected to-day. 



It is easy to say that the blackness of the negro's skin was produced 

 by the tropical sun, and that it is now part of his natural inheritance. 

 It is easy to say this, but absolutely futile. Let us first catch our 

 modifications. 



The Golden Rod (Solidago virgaurea) growing on the Alps is pre- 

 cocious in its flowering when compared with representatives of the 

 same species growing in the lowlands. Hoffmann found that Alpine 

 forms transplanted to Giessen remained precocious, therefore the 

 acquired precocity had become heritable. But there is no evidence 

 that the precocity was acquired ; it may have been the outcome of the 

 selection of germinal variations. 



The African Wart-hog (Phacochoerus) has the peculiar habit of 

 kneeling down on its fore-limbs as it routs with its huge tusks in the 

 ground and pushes itself forward with its hind-limbs. It has strong 

 horny callosities protecting the surfaces on which it kneels, and these 

 are seen even in the embryos. This seems to some naturalists to be a 

 satisfactory proof of the inheritance of an acquired character. It is to 

 others simply an instance of an adaptive peculiarity of germinal origin 

 wrought out by natural selection. 



