THE METHOD OF EVOLUTION g 



is one which, in common parlance, arises in the 

 individual "by nature." Thus arms, legs, eyes, 

 ears, head, etc., are all inborn characters. The 

 child inherits them from his parent. But, if during 

 its development, or after the completion of the 

 development, any one of the inborn characters of 

 an individual is modified by some occurrence, the 

 change thus produced is known as an acquired 

 character, or, shortly, as an acquirement. Thus 

 all the effects of exercise are acquirements ; for 

 example, the enlargement which exercise causes in 

 muscles. The effects of lack of exercise are also 

 acquirements, for example, the wasting of a disused 

 muscle. The effects of injury are acquirements, 

 for example, the changes in a diseased lung or 

 injured arm. Every modification of the mind is 

 also an acquirement, for example, everything stored 

 within the memory. If a man be blinded by 

 accident or disease, his blindness is acquired. But 

 if he come into the world blind, if he be blind by 

 nature, his blindness is inborn. If a son be 

 naturally smaller than his father, then his inferiority 

 of size is inborn ; but if his growth be stunted by 

 ill-health or lack of nourishment or exercise, his 

 inferiority is acquired. 



biological meaning. The wooUiness of the hair of negroes was 

 presumably inborn from the very beginning. But, if a man by some 

 process changed his straight hair to wool, the wooUiness would, in 

 that case, be an acquirement, 



