VI KWS OF LAMARCK 381 



is nothing absurd in them, and at the time when Lamarck wrote 

 it would scarcely have been possible to formulate anything 

 better. 



It is, however, this assumption of the inheritance of somato- 

 genic characters that has probably done more than anything else 

 to prevent many modern biologists from accepting the so-called 

 Lamarckian factors of evolution. Those who hold with Weis- 

 mann that there is no possible mechanism by which a somato- 

 genic character can be converted into a blastogenic one are 

 forced to reject Lamarck's teaching, but the Weismannian 

 assumption that there is no such possibility of inheritance of 

 somatogenic characters rests upon no better foundation than the 

 Lamarckian assumption that there is. We have dealt with this 

 question at some length in an earlier chapter and need only now 

 remember that, if there are many modern biologists who reject 

 the Lamarckian factors because they cannot reconcile them with 

 Weismannism, there are probably quite as many others who 

 accept them because they appeal irresistibly to their common 

 sense, and because they refuse to believe that Weismann's 

 difficulties are really insurmountable. 



It is, of course, easy to ridicule Lamarck's views, and to say, 

 for example, that he maintained that an animal could develop 

 an organ by simply wishing for it, and ridicule of this kind has 

 undoubtedly done much to hinder the due appreciation of his 

 work. Such statements, however, are only made by those who 

 have never paid adequate attention to the writings of the great 

 French biologist. 



It is evident from the passage last quoted that Lamarck also 

 did not fail to perceive the importance of isolation as a factor in 

 organic evolution, necessary to prevent the swampin effects of 

 intercrossing upon newly arisen species or varieties. 



In another place he discusses the influence of the struggle for 

 existence in counteracting the effects of excessive multiplication, 

 and in so doing just misses the idea of Natural Selection : 



" Animals eat one another, except those which live only upon 

 plants ; but the latter are liable to be devoured by carnivores. 



" We know that it is the stronger and the better armed which 

 eat the weaker, and that the large species devour the smaller 

 ones. Nevertheless the individuals of one and the same race 

 rarely eat each other ; they make war on other races." l 



1 Op. tit., Tom. I, p. 99. 



