Acquired Characters 27 



necessary characters. It is a well-known fact 

 that males are more variable than females and 

 that new qualities are usually first acquired by 

 them. Females then acquire what has proved 

 useful, representing in their progress the net 

 results of past development as it is shown 

 in inherited structure. The order of the 

 change from acquired to natural characters is : 

 first, a surplus of energy following acquired 

 characters ; second, the expression of this 

 energy in the secondary sexual characters of 

 the males ; third, the discovery of some use for 

 these secondary characters in which the whole 

 race or species can participate; and fourth, 

 their appearance through heredity in all indi- 

 viduals of the species, whereupon they cease to 

 be secondary and become primary characters. 

 /\ We note here three kinds of characters 

 primary, acquired, and secondary. The pri- 

 mary are those at a given moment necessary to 

 the existence of an organism. The acquired 

 are those due to individual action, and they are 

 propagated by imitation, forethought, or some 

 other conscious means. " The secondary result 

 from the success of the acquired characters in 



