Page:The Zoologist, 4th series, vol 2 (1898).djvu/493

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ASSIMILATIVE COLOURATION.
461

Dr. Hans Meyer remarks that "every observer must be struck with the general similarity in colour and partly also in form of the larger African mammals to the prevailing colours and features of the regions they frequent. At a distance it is scarcely possible to tell a Hartebeest at rest from one of the reddish ant-heaps which everywhere abound; the long-legged, long-necked Giraffe might easily pass for a dead mimosa, the Khinoceros for a fallen trunk, the grey-brown Zebra for a clump of grass or thorn scrub. It is only their movements that betray their real character."[1] The Lichtenstein Hartebeest (Bubalis lichtensteini) is also of a more or less uniform colour, "saffron, with a golden tinge throughout"; while the more common Hartebeest (Bubalis caama), which has a wider distribution, is also in general colour of a "reddish brown, with violet tinge throughout"; and Messrs. Nicolls and Eglington, who have been quoted as to the colour of both these animals, describing the habits of the last, write:—"The Hartebeest is never met with in very thick bush, or hilly country, but frequents either the bare open flats or plains sparsely covered with camel-thorn trees (Acacia giraffæ), and where there are treeless glades to be met with."[2]

It may have possibly struck the reader by this time that the surmise of the writer is that, in the first instance, and in the long past, animals were uniformly and assimilatively coloured in connection with their principal surroundings, and that as they migrated through scarcity of food owing to excessive multiplication or other causes, or through the alteration of climatic condition, their changed environment placed them under altogether different conditions, and the modifying influence of natural selection then became a magician's wand in the evolution of diverse colours and markings, but it was not the sole agency. The tendency to explain all problems by the theory of natural selection is to-day greatly retarding the study of bionomics. It is not one whit removed from the proferred explanation of the old teleologists, and represents as little

  1. 'Across East African Glaciers,' p. 79.—Other travellers in South Africa have noticed an absence of game among ant-hills. Thus Andrew Steedman states: "We remarked that, where they most abounded, Antelopes and other species of gregarious animals were seldom to be met with " (' Wand, and Advent, in Int. S. Africa,' vol. i. p. 172).
  2. 'The Sportsman in South Africa,' p. 46.