512 THE BUTTERFLIES OF NEW ENGLAND. 



scales, including all the pigment of the wings, are completely developed, 

 the insect appearing full-fledged and perfectly caj^arisoned, subject to no 

 further change. 



Nevertheless, the general phenomena of ornamentation in vertebrates 

 are so exactly repeated in butterflies that no one can plausibly claim that 

 these phenomena originate, in the two groups, in distinct proximate 

 causes. Even the same relation of color to locality, which has been so 

 well brought out by ]Mr. J. A. Allen in various papers upon our native 

 birds and mammals, reappears in butterflies. It would, therefore, seem 

 not unlikely that we shall be forced to discard the idea of direct physical 

 causation in the one case as in the other. 



I have seen only a single attempt to trace the origin of the color- 

 patterns of butterflies by the light of modern ideas. This was the subject 

 of a short article by Rev. Mr. Higgins, published some years ago in the 

 Quarterly Journal of Science. This writer maintains that what he terms 

 the primary or fundamental pattern was a "pale ground with darker linear 

 markings following the course of the viens" ; and he explains its origin 

 from the earliest monochromatic wing, by supposing that "the scales 

 growing on the membrane upon or near the veins would be distinguished 

 from the scales growing on other parts of the membrane by a freer devel- 

 opment of pigmentary matter" within them. From this simple form of 

 linear markings he would derive all those patterns which bear definite rela- 

 tions to the veins, such as the dark bands which cross them at an angle 

 and are scalloped between each pair ; thus he says : "a portion of the dark 

 scales begin to diverge on each side from the veins," and "the dark lines 

 thus formed will meet in the middle of the areas between the veins, pro- 

 ducing a band of scallops." But all the lighter-colored and more brilliant 

 spots he would derive from modifications in the extent and intensity of the 

 ground-color, or, as he afterward terms it, the "blush." 



It will hardly be worth while to follow his line of argument ; for, plausi- 

 ble and simple as this hypothesis appears at first glance, it is unsatisfac- 

 tory. An examination of an extensive series of specimens and illustrations 

 convinces me that an even simpler explanation can be given, in which the 

 darker and lighter markings have a common origin. Moreover there are 

 definite objections to Mr. Higgins's theory. Its basis, that the scales 

 next the veins would have a freer development of pigmentary matter 

 within them, although perhaps true, is a pure assumption, to support which 

 no facts are given. His observations are drawn wholly from butterflies, 

 with no reference to the ornamentation of moths, which naturally would 

 give some clue to the previous simpler condition of butterflies ; and finally, 

 if the earliest form of ornamentation were linear markings on a pale 

 ground, from which the scalloped l^ands were derived, w^e ought now to 

 find, as one form of variation, transverse series of dark spots seated on 



