CONSCIOUS PROTECTIVE RESEMBLANCE. 539 
For instance, in those wonderful cases which are found so frequently 
among insects, the habits of each species are so intimately correlated 
with its abnormal structure and colouring,‘ that it is unreasonable to 
believe that these characters have been developed independently by 
different factors; the latter by natural selection, and the former by the 
‘evolution of active mimicry,’ whatever that may mean. These 
special structures cannot be accounted for by ‘‘ active mimicry,” neither 
can they be explained by any general theory of internal or external 
causes, for, as the late Mr. Romanes hag well remarked, ‘‘ Were it not 
that some of Darwin’s critics have overlooked the very point wherein 
the great value of protective colouring as evidence of natural selection 
consists, it would be needless to observe that it does so tin the minute- 
ness of the protective resemblance which in so many cases is presented. 
Of course, where the resemblance is only very general, the phenomena 
might be ascribed to mere coincidence, of which the instincts of the 
animal have taken advantage. But in the measure that the resem- 
blance becomes minutely detailed, the supposition of mere coincidence 
is excluded, and the agency of some specially adaptive cause de- 
monstrated ” (‘Darwin and after Darwin,’ p. 318, note). 
Thus a strong objection may be lodged against the whole suggestion 
of active mimicry, as opposed to that of natural selection, in that 
the former suggestion is essentially incomplete and cannot explain all 
the facts of the case. Let us take the instance of the leaf-butterflies 
of the genus Kallima, of which Mr. Distant says: “The partiality of 
this insect for settling on dry and withered leaves appears a true 
instance of active mimicry ”’ (/. c., 1899, p. 581). Upon the theory of 
natural selection (granted the undisputed facts of variation and the 
struggle for existence), it is easy to understand that any marked varia- 
tions in the direction of leaf-like shapes or markings, which would 
afford better concealment, would tend to be preserved and further 
augmented, both by heredity and by the increased keenness of enemies, 
until the present admirable resemblance had been arrived at. ‘‘ But, 
as Mr. Badenoch has well enquired, ‘Of what avail would be the dis- 
guise were the insect prone to settle upon a flower, or green leaf, or 
other inappropriate surface ?’”’ (/. c.). Quite true; and the fact that 
the insect is not so inclined is readily explainable by the Darwinian 
theory ; for it is clear that a much greater proportion of those 
individuals which were prone to render themselves conspicuous by 
settling on inappropriate surfaces would be picked off by their enemies 
than of those which selected suitable resting places; and thus, by a 
gradual process of elimination, the progeny of those individuals, which 
possessed a well-defined instinct to settle upon withered leaves, &c., 
