CHAPTER VIII 



ARE ACQUIRED MODIFICATIONS 

 HERITABLE ? 



One of the very live questions in heredity at 

 the present time is whether or not acquired 

 modifications can be transmitted from parents 

 to offspring. The term "acquired modifica- 

 tion" or "acquired character" is used with a 

 very definite meaning in all discussions of 

 heredity. In one sense all new characters are 

 acquired. If we believe in the derivation of 

 the more complex animals and plants from 

 relatively simple types (the doctrine of evolu- 

 tion), evidently the characters which later 

 animals come to possess are not possessed by 

 the earlier forms from which they are derived. 

 Thus in the early rock strata we find no verte- 

 brate animals; later the vertebrates appeared. 

 The vertebrate character is one, therefore, that 

 was acquired by the animals in due course of 

 time. It is not, in this sense, however, that 



