Note 39 — Chapter VII

The male of polytes (Pl. V, fig. 1) is a handsome blackish insect with a wing expanse of about four inches. With the exception of some yellowish-white spots along their outer margin the fore wings are entirely dark. Similar spots occur along the margin of the hind wing also, while across the middle runs a series of six yellowish-white patches producing the appearance of a broad light band. The thorax and abdomen are full black, though the black of the head is relieved by a few lighter yellowish scales. The under surface is much like the upper, the chief difference being a series of small and slightly reddish lunules running outside the light band near the margin of the hind wing (Pl. V, fig. 1 a). In some specimens these markings are almost absent. One form of female is almost exactly like the male (Pl. V, fig. 2), the one slight difference being that the lunules on the under surface of the hind wing are generally a trifle larger. For brevity she may be called the M form. The second form of female differs in many respects from the male and the M female. Instead of being quite dark, the fore wings are marked by darker ribbed lines on a lighter ground[39] (Pl. V, fig. 3). The hind wings shew several marked differences from those of the male. Of the series of six patches forming the cross band the outermost has nearly disappeared, and the innermost has become smaller and reddish. The middle four, on the other hand, have become deeper, reaching up towards the insertion of the wing, and are pure white. A series of red lunules occurs on the upper surface outside the white band, and the yellowish-white marginal markings tend to become red. These differences are equally well marked on the under surface (Pl. V, fig. 3 a). The colour of the body, however, remains as in the male. From the resemblance shewn by this form to another species of Swallow-tail, Papilio aristolochiae (Pl. V, fig. 5), we shall speak of it as the A form.