Page:The Zoologist, 4th series, vol 4 (1900).djvu/581

Rh to certain cases which are generally referred to protective resemblance. After stating that "colour alone may prove a false analogy to protection" (l.c., p. 350), and referring to the strongly protective colouring of a certain South American butterfly, Ageronia feronica, he says:

"This observer, however, at the same time refers to the statement of Bigg Wither, that this very insect is called the Whip-Butterfly, owing to the sharp whip-cracking sound made by its wings when battling by its fellows in the air,(n13) and that this sound makes it the easy prey of a forest bird, locally known as 'the Suruqua,' who thus detects and secures it. Here the apparent protection by "protective resemblance" is invalidated by a peculiar and unusual sound-producing quality, which is as equally dangerous as its colour is reported protective. A similar remark may be made as to the musical Cicadidæ. How often have the usual green and brown colours of these insects been adduced as an example of protective resemblance;... but when we desire to capture them the shrill noise proclaims their retreat, and their assimilative colouration avails them little." Again, in commenting upon Mr. Tutt's graphic account of the protective colouring of the Lappet Moth (Lasiocampa quercifolia), he says: "Here the expression, 'trained eye,' of the entomologist, would suggest a more developed 'trained eye' of the moth's natural enemies, and hence any theory of protective mimicry is much discounted (l.c. p. 455). From these quotations it may be gathered that Mr. Distant's attitude towards the subject is somewhat as follows:—When we find that the colouring of any animal assimilates well with that of its environment, but, at the same time, that this animal is apt to render itself more or less noticeable by certain movements or noises, then we are not justified in regarding its colouration as an efficient protection, and the case must therefore be removed from the category of protective resemblance. Tempting as such a conclusion may be to the opponents of Darwinism, it appears to me to be wholly erroneous. The fundamental fallacy lies in the gratuitous assumption that the protection afforded must be absolute; for otherwise there is no ground whatever for the objection raised. In the first place, I am not aware that such absolute protection has been anywhere observed in nature, and, indeed, were the above proposition a sound one, the principle of protective resemblance would have to be entirely abandoned. But, as a matter of fact, this principle predicates no such complete immunity from attack; in truth, the very essence of the theory of natural selection negatives any such