THE CORAL SNAKE “MIMIC” PROBLEM IN PANAMÁ

The student of evolution, if his attention is called to contemporary phenomena in the Animal Kingdom, cannot fail to note cases of extraordinary superficial resemblance between animals of quite diverse relationships. The term "mimicry" and a voluminous body of literature has resulted. In the most general terms "mimicry" may be called a word to describe a situation (or an evolutionary problem) in. which external appearance, confined to a certain area and a certain size range, is shared by species of diverse ancestry. In many of these situations (and the coral snake problem is a case in point) some species are definitely venomous, poisonous, or distasteful as food while others are innocuous and edible. In all these situations the evolutionary problem of the superficial resemblance (the observational data) challenges the evolutionary student. An almost complete acquaintance with the history, facts, and status of the coral snake mimic problem may be gained by the perusal of four papers; those of Cope 1860, Wallace 1867, Gadow 1911, and Sternfeld 1913. Cope first called attention to the existence of the problem in the following words (p. 262): "The subject of the prevalence of peculiar shades and arrangements of colors throughout certain geographical districts is one of much interest to the zoologists," "the Elaps of South America is represented in the same region by the black and red ringed Oxyrhopes, the Erythrolamprus, Pliocercus, Lampropeltis, etc." Wallace, in discussing the problem, proposed a solution: "a very remarkable and instructive case of true mimicry." Gadow, writing after extensive field experience in Mexico, objected to the idea of mimicry on a number of grounds as follows: "There are more mimickers . . . than species of Elaps," "there are large districts of unquestionably Elaps-terrain where the harmless species and individuals form the great majority." "The range of harmless species in the typical dress of Elaps often extends far beyond that of the nearest species of Elaps." "I have not yet come across a single instance of what may be called occurrence side by side." This in spite of the fact that he had previously written (1908) "several kinds of harmless snakes, belonging to different groups, inhabit the same districts together with the poisonous coral snake, and, what is more, they lead the same kind of life under rotten stumps and in ants nests." He proposed two other solutions, as follows: (1) "at dusk . . . black, alternating with red produces an effacive blur"; i.e., the coloration of these snakes is concealing; and (2) "because the America [sic] environment favours the production of red in snakes . . . the Scientist . . . means, but does not like to say: Genius loci." Sternfeld's paper is a defense of mimicry against some of Gadow's criticisms, and an attack on the second of Gadow's solutions. He suggests that superiority in the number of species of mimics over coral snakes is a point in favor of, not against, mimicry. He claims that the coincidence of range is much better than Gadow implied, and adds the important point of coincidence in size, the coral snake coloration being manifested only in snakes of coral snake dimensions. Gadow's "side by side" criticism he considers absurd, and ridicules it in the most amusing paragraph I have ever read in a scientific paper. With regard to the environment in America and the "Genius loci" he says, concerning this "geheimii-