. The Cambridge natural history. Zoology. SCALES 331. Socket holding the stalk in Galleria mellonella; B, insertion of the scale of Polyommiatus phloeas. b, Base of scale ; r, holding-ring ; 7U, snrface of wing. (After Spuler.) giving rise to metallic " ; The walls of the scales are themselves, in some cases, tinted with pigment. It is said that some of the scales contain air, and that the glistening- whiteness of certain scales is due to this. The exposed surface of the scale usually differs from the surface that is pressed down on the wing in being delicately a
. The Cambridge natural history. Zoology. SCALES 331. Socket holding the stalk in Galleria mellonella; B, insertion of the scale of Polyommiatus phloeas. b, Base of scale ; r, holding-ring ; 7U, snrface of wing. (After Spuler.) giving rise to metallic " ; The walls of the scales are themselves, in some cases, tinted with pigment. It is said that some of the scales contain air, and that the glistening- whiteness of certain scales is due to this. The exposed surface of the scale usually differs from the surface that is pressed down on the wing in being delicately and regularly striated; the colours of the upper and under surfaces of a scale may also be quite different. Scales are essentially of the nature of hairs, and all the transitions between hairs and yib. 172. — insertion of scales, a, true scales may be found on the wings of certain Lepidoptera that bsar both hairs and scales, lihpmia. It has been calculated that there are a million and a half of scales on the wings of an individual of the genus Morplw. The scales are arranged on the wing in an overlapping manner, somewhat like slates on the roof of a house. Each scale has a short stalk, and is maintained in position by the stalk fitting into a cavity in a projection of the wing-membrane (Fig. 172). Androconia.—The males of numerous butterfiies possess scales peculiar in kind and various in arrangement. They may be either irregularly scattered over the wing, or they may form very complex definite structures (Fig. 173). They were formerly called " plumules," but Scudder has replaced this name by the better one, "; The function of the androconia is still obscure. An odour is believed to be connected with them. Thomas supposes ^ that these scales are hollow tubes in connec- tion with glands at their bases, and that matter secreted by the glands passes through the scales and becomes diffused. In nearly all Lepidoptera it is the male that seeks t
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1895
