Page:The Zoologist, 4th series, vol 4 (1900).djvu/157

Rh The test of protection is concealment from the keen search of enemies, not merely an assimilative process, as noted by casual observers. Of course a partial concealment is a partial protection, but it is difficult to see how this applies to the Hare, and in the Transvaal, where most of these lines were written, I found it as foolish an animal, and one as easy to discover and shoot, as in England. Dietrich de Winckell, who according to Prince Kropotkin "is considered to be among the best acquainted with the habits of Hares, describes them as passionate players, becoming so intoxicated by their play that a Hare has been known to take an approaching Fox for a playmate." Describers are often carried away by their enthusiasm for the theory of mimicry and give their pens great licence. Thus, Dr. Meyer, speaking of the neighbourhood of Kilima-njaro, writes: "The insects, too, have their 'magic mantle' of invisibility. No wonder it is difficult to make a collection, when the Butterflies and Crickets look like leaves and dry blades, the Cicadæ like leaf-stems, the Spiders like thorns, the Phasmodeæ like bare twigs, the Beetles like stones and bits of earth, the Moths like mosses and lichens." Much, very much, has been made of the mimetic resemblance of the upper surface of Flatfishes to the bottom on which they rest. Mr. C.L. Jackson has given the result of a most interesting experiment he made by placing a number of small Flatfish in a tank which contained ten or twelve large Cod averaging fully twenty pounds weight each. These at once dashed after the Flatfish, "which instantly covered themselves with sand and apparently disappeared. The Cod, however, knew better. They commenced to hunt for them, carefully and systematically quartering their ground as a well-trained pointer would do, and affording a beautiful illustration of the use of the curious 'beard' possessed by many members of the Cod family. By-and-by, one of them, by means of this feeler, detected one of the Zool. 4th ser. vol. IV., March, 1900.