Page:The Zoologist, 4th series, vol 3 (1899).djvu/339

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MIMICRY.
313

bird-nesting boy, who with difficulty succeeds in making the town lad see the concealed nest he is about to take; or the experienced eye of the angler which recognizes the Trout, undetected by the ordinary walker on the bank. Or again, watch the rambles of the out-door collector and the closet-naturalist; or the entomologist who discovers and captures, and the other entomologist who only classifies and describes. It is the old remark of "Eyes" and "No Eyes."[1] If then we can for the purpose of sport or science pit our discerning faculties against the extreme power of animal disguises,[2] how much more must that detective discrimination have been acquired by those creatures whose very lives are so largely passed in the search, and depend on the capture of these mimicking fugitives. Even the obscure Coccids are preyed upon by birds. Mr. Newstead found specimens in the stomach of the Blue Tit (Parus cæruleus), and remarks:—"These birds must have keen eyes to distinguish this species, for it is well protected both in colour and texture. The central red-brown speck in the scale is the only indication of its presence, and altogether it may be considered the best protected of any of our British Coccidæ."[3] Again, birds learn to recognise hurtful as well as advantageous objects as exemplified by telegraph wires. When these were first elevated they caused great mortality among birds which flew against them, but after a time the wires were avoided, and that loss in avian life was vastly reduced. Birds certainly acquire experience and avoid dangerous food. Frank Buckland relates that a keeper at Castle Forbes poisoned dead Rabbits, and "picked up as many as twenty-one Magpies and Crows to one Rabbit at one time." But "the cunning birds found out that it was dangerous to peck at dead Rabbits, in vain therefore were they laid down; the Crows and Magpies were for a season triumphant. But the keeper

  1. Tennyson was an acute observer of nature. He once asked Miss Thackeray to notice whether the Sky-Lark did not come down sideways on the wing. (W.J. Dawson, 'The Makers of Modern English,' 3rd edit. p. 182.)
  2. My friend Dr. Percy Rendall, then at Barberton in the Transvaal, a most enthusiastic and successful collector, in reply to my expressed wish that he would still keep a sharp look-out for Phasmidæ, replied: "I am keenly on the look-out for them, and will in most cases back my eyes against almost any kind of insect protective resemblance dodges."
  3. 'Entomol. Month. Mag.,' ser. 2, vol. vi. p. 85.