SEXUAL SELECTION 297 



Agelceus phceniceus tlie males liave had their colors greatly 

 intensified in the south; whereas with Cardinalis virginianus 

 it is the females which have been thus affected; with 

 Quiscalus major the females have been rendered extremely 

 variable in tint, while the males remain nearly uniform." 



A few exceptional cases occur in various classes of 

 animals, in which the females instead of the males have 

 acquired well pronounced secondary sexual characters, 

 such as brighter colors, greater size, strength, or pugnacity. 

 With birds there has sometimes been a complete transpo- 

 sition of the ordinary characters proper to each sex;, the 

 females having become the more eager in courtship, the 

 males remaining comparatively passive, but apparently 

 selecting the more attractive females, as we may infer from 

 the results. Certain hen birds have thus been rendered more 

 highly colored or otherwise ornamented, as well as more 

 powerful and pugnacious than the cocks; these characters 

 being transmitted to the female offspring alone. 



It may be suggested that in some cases a double process 

 of selection has been carried on ; that the males have selected 

 the more attractive females, and the latter the more attrac- 

 tive males. This process, however, though it might lead 

 to the modification of both sexes, would not make the one 

 sex different from the other, unless indeed their tastes for 

 the beautiful differed; but this is a supposition too improb- 

 able to be worth considering in the case of any animal, ex- 

 cepting man. There are, however, many animals in which 

 the sexes resemble each other, both being furnished with 

 the same ornaments, which analogy would lead us to attrib- 

 ute to the agency of sexual selection. In such cases it may 

 be suggested with more plausibility, that there has been a 

 double or mutual process of sexual selection; the more 

 vigorous and precocious females selecting the more attrac- 

 tive and vigorous males, the latter rejecting all except the 

 more attractive females. But from what we know of the 



»' "Mammals and Birds of B. Florida," pp. 234, 280, 295. 



