60 ELK.MKXTARY WTUDIKS IN INSECT LIFE 



welfare and existence of this species of butterfly. Other 

 butterflies have not the power to emit this noxious odor 

 and distasteful fluid as a means of protection; but some 

 of them have succeeded by slow and gradual changes in 

 assuming colors closely resembling those of the more 

 favored species. 



Most remarkable among these is the simulation of 

 the viceroy butterfly. 1 On account of its relation to the 

 milkweed butterfly it has been fitly termed the viceroy, 

 and the milkweed butterfly has been called the monarch. 

 As will be seen from the illustrations (Figs. 48 a, 6), the 

 general appearance of the two is much the same. The 

 viceroy, however, is smaller, and bears a transverse 

 black band upou the hind wing. This butterfly was 

 once much darker than it is now. The brown color 

 was present in a small degree, and this coloring has 

 increased by natural selection until we have the present 

 protective form. ]Ias this change of color been carried 

 on through the conscious activity of the insect '( In other 

 words, "Can the Ethiopian change his skin, or the 

 leopard his spots ( " Mimicry is not consciously carried 

 on, but has to be accounted for by natural selection; 

 that is, those viceroys having the greater amount of 

 brown were more likelv to decei\v the birds than those 



. 



with less, -consequently they lived to reproduce in 

 kind other- with prominent brown markings, and among 

 them those displaying the brown most prominently 

 were most likely to live to reproduce again in turn, the 

 brown colors increasing, and so through a long series 



l Basil(irchia archippus. 



