Page:The Zoologist, 4th series, vol 2 (1898).djvu/416

384 must have developed; and this we may imagine to have been of an assimilative hue, for, as Poulton has remarked, "all animal colour must have been originally non-significant; for, although selective agencies have found manifold uses for colour, this fact can never have accounted for its first appearance." We may think with Grant Allen, who asserts of the unbroken green hue which was the dominant feature of the flowerless carboniferous era: "Equally unvaried, no doubt, was the hue of the articulate creatures which fed amid those green jungles of tangled fern and club-moss. A few scorpion-like insects, an occasional cockroach, beetle, or other uncanny creeping thing may still be detected in the debris of a forgotten world; but no trace of a bee, a moth, or a joyous butterfly can be discovered in these earliest ages of animal life." Many phases of plant-life can only be understood by a knowledge of past geological conditions. Mr. Harshberger, of Pennsylvania, has recently discussed the origin of the vernal flora of his own land, and has apparently shown that the flowering time of many plants and trees is a direct product of heredity from the glacial period. It therefore seems possible that assimilative colouration may have been a first and very general consequent in animal development; that such a view is suggested by many facts; and that the subsequent protective resemblance acquired by numerous living creatures through the process of natural selection, when life had advanced to the competitive stage, is far too frequently used as an explanation for whole series of uniform phenomena in colouration, which have probably survived unaltered from remote antiquity, and which by their very essence were "outside the law" of natural selection, or un-