Color and Pattern and their Uses 
612 
degree of specialization has been assumed, by nearly all upholders of the 
use hypotheses, to be natural selection. This agent can account for pur¬ 
posefulness, which is obviously an inherent part of all the hypotheses. And 
no other suggested agent can. Weismann makes, indeed, of this fact, by 
inverting the problem, one of his most effective arguments for the potency 
and Allmacht of natural selection. He declares that the existence of 
special protective resemblance, warning colors, and mimicry proves the 
reality of selection. But it must be asked, while admitting the cogency of 
much of the argument for natural selection as the efficient cause of high 
specialization of color and pattern as we have seen it actually to exist, how 
such a condition as that shown by the mimicking viceroy butterfly has come 
to be gradually developed, gradual development being confessedly selection’s 
Fig. 796.—The owl-butterfly, Caligo sp., under side. (Two-thirds natural size; photo¬ 
graph by the author.) 
only mode of working. Could the viceroy have had any protection for itself, 
any advantage at all, until it actually so nearly resembled the inedible mon¬ 
arch as to be mistaken for it? No slight tinge of brown on the black and 
white wings (typical color scheme of the genus), no slight change of mark¬ 
ing would be of any service in making the viceroy a mimic of the monarch. 
The whole leap from typical Basilarchia to (apparently) typical Anosia had 
to be made practically at once. On the other hand is it necessary for Kallima, 
