WEISMAXN'S ESSAY'S UPON HEREDITY. 15 



ter which appears in one of the parents rriay not 

 reappear in the child, but that nothing can arise in 

 any organism unless the predisposition is already 

 present, and it is the predisposition which is trans- 

 mitted, not the character : 



" Only those characters can be called ' acquired ' which 

 owe their origin to external influences, and the term 

 'acquired' must be denied to those which depend upon the 

 mysterious relationship between the different hereditary 

 tendencies which meet in the fertilized ovum. These latter 

 are not ' acquired,' but inherited, although the ancestors did 

 not possess them as such, but only as it were the elements 

 of which they are composed." 



With regard to changes produced in the indi- 

 vidual by external influences, these, according to 

 Professor Weismann, cannot be transmitted to the 

 germs, and therefore cannot be hereditary. No 

 one expects a cat whose tail has been cut off to 

 become the parent of tailless kittens, though there 

 are always old wives' fables to that effect ; nor do 

 we expect a man who has lost an arm in battle to 

 have a family of one-armed children. Even the 

 tyranny of fashion seems powerless to affect the 

 germ-plasm. The deformed foot of the Chinese 

 mother is not transmitted to her children, nor have 

 centuries of Western civilization had the slightest 

 influence on the waist of the British baby. Professor 

 Weismann has an elaborate examination of the 

 various cases of supposed transmission of mutila- 

 tions, including the case of epilepsy artificially 



