NEO-LAMARCKIANISM. 26$ 



mies by running from them. This is the effort 

 on the part of the animal ; but the result is the 

 strengthening and increase in size of the muscles of 

 the legs, and the individuals become better adapted 

 for running. And so in general. The effort is to 

 satisfy certain wants, and the result is the develop- 

 ment of new activities. Hence the modification of 

 organs by use. 



To make this theory of use and effort of any 

 significance (the same may be said in regard to 

 Darwin's theory), it is necessary to assume that 

 the child has a tendency to inherit these pecu- 

 liarities at an earlier age than they were acquired 

 by the parent. This law, which is called the law 

 of accelerated development, causes the variations 

 arising by use or otherwise to be inherited at 

 earlier and earlier ages as generations go by. An 

 increase in the size of an organ first acquired in 

 middle life would, after a number of generations, be 

 possessed by the young. For example : the large 

 arm of the blacksmith is acquired during manhood, 

 but, according to the law in question, the children 

 would have a tendency to develop this large arm at 

 a slightly earlier period. If they followed the same 

 trade, their children would inherit the same peculi- 

 arities still earlier. And if the family continued to 

 follow the trade of blacksmith, the peculiarity would 

 be carried back to the young, and the children 

 would show from their birth that they were black- 

 smiths. This principle of acceleration is believed 

 by some to be universal. By others it is regarded 

 as not universal, since in certain cases they think an 



