The Inheritance of Acquired Characters 57 



tion. He claims that we should not expect the inheritance of 

 short tails, because even if such an influence were transmitted 

 to the egg, the young embryo would promptly regenerate its 

 missing portions. Unfortunately there is no evidence that they 

 can regenerate in the embryo. 



It has been claimed that the removal of or injury to an organ 

 is a different process from the modification of an organ caused by 

 some external condition. There are, however, cases in which 

 an organ has been greatly modified for several generations and 

 no inherited effect has been produced. The feet of Chinese 

 women are compressed so that their form is greatly changed, 

 and in the higher classes this has been kept up for generations, 

 yet no effect has been produced on the feet of the children. 

 Certain races of Indians are known to have changed the shape 

 of the heads of their children by compressing them between 

 boards, yet the effect does not seem to have been inherited. 

 Tight lacing may change very greatly the shape of the ribs and 

 to some, extent the position of the viscera, yet no inherited effect 

 has been produced. 



We may now consider the cases of the supposed inherited 

 effect of use and of disuse. We are famihar with the decrease 

 of a part in size and in function through disuse, in the case of 

 muscles, glands, bones, etc., and also with the enlargement of 

 organs through use. It is especially this class of facts that 

 impressed Lamarck, and which led him to assume that these 

 effects are inherited. The rudimentary eyes of animals living 

 in the dark are often cited as having resulted from disuse. The 

 long neck of the giraffe and the long tongue of the ant-eater, of 

 humming birds, and of woodpeckers are examples, that La- 

 marck has given, of effects produced by use; and many natu- 

 ralists since Lamarck's time have cited these and other similar 

 cases as bearing on the question. But neither Lamarck nor 

 his successors have been able to demonstrate by experiment 

 that the effects of use and disuse of this kind are inherited by 

 the next generation, and until this proof is forthcoming we 

 must regard their view as purely speculative. It is surprising 



