|from Hugh B. Cott, Adaptive Coloration in Animals (1940)|
Reproduced above is one of my favorite drawings from what is one of my favorite books. It is a cluster of drawings of the "hind limbs of the Common Frog (Rana temporaria), showing coincident disruptive pattern[s]." They are one of about 150 illustrations of natural camouflage in Hugh B. Cott's well-known classic book about that fascinating subject, titled Adaptive Coloration in Animals (London: Methuen, 1940). What makes these drawings (and the book itself) even more interesting is that Cott (1900-1987) was not just a zoologist—he was a highly skilled scientific illustrator (these are his own pen-and-ink drawings), a wildlife photographer, and a prominent British camoufleur in World War II.
In these drawings, he is trying to show how disruptive patterns in animal forms combine with continuous patterns to produce an effect that Cott referred to as coincident disruption. As he so aptly explained it, disruptive patterns work "by the optical destruction of what is present," while continuous patterns work "by the optical construction of what is not present." He then concludes that "while disruptive patterns appear to break up what is really a continuous surface, coincident patterns seem to unite what are actually discontinuous surfaces" (p. 70).
This same illustration was also recently reproduced in the new book by art historian Ann Elias, Camouflage Australia (Sydney University Press, 2011). Having followed her research in recent years, I was delighted to be asked to write a preface for the book, which is an admirable achievement in interdisciplinary research. In the preface, I could not resist the temptation to compare Elias' own efforts to Cott's drawing of the frogs' hind limbs. The author, I said, "has folded up a lengthy limb of scholarly tradition (made up of sacrosanct disciplines like aesthetics, zoology, anthropology and sociology), in order to reveal new zones that are cross-disciplinary" (p. viii).