SPHINGIDES. 379 



marked in this superfamily. In those species that feed, both sexes 

 fly actively and the antennae of both sexes are very similar — Sesiids 

 (Macroglossids), Eumorphids, Sphingids (sens, strict.), etc. In those 

 that do not feed, both sexes are comparatively sluggish, the females 

 particularly so, the males being driven to a more active condition 

 on account of their having to seek the females, and here there 

 is somewhat more sexual difference in antennal structure, e.g., 

 Amorphids. 



One may note with regard to the specialisation of the body scales 

 that they are closely appressed to the body, thus forming a smooth 

 continuous coat of mail that evidently offers less resistance to its 

 passage through the air than a body covered with a mass of 

 assurgent hairs. This must certainly be of advantage to a swift-flying 

 moth, e.g., Sphinx, Choerocampa, etc., whilst the protection given 

 by such a clothing must also be considerable. Kellogg states 

 that the scales on the forewings are usually more specialised than 

 those on the hindwings, both in form and arrangement, and that 

 the scale-specialisation is higher in moths of highly-specialised flight- 

 function (indicated by cephalisation of flight) than in moths of more 

 generalised flight-function, as, for example, the Sphingids compared 

 with the Attacids. He then adds (Taxonomic Value of Scales of 

 Lepidoptera, pp. 56-57) : "The hindwings of moths, where an extreme 

 cephalisation of flight has been arrived at, show a less specialisation 

 of the scale-covering than is shown by the hindwings of moths 

 whose flight-function is not so excessively cephalised, which, indeed, 

 is to be expected, because of the lesser importance of the hind- 

 wings in cases of extreme cephalisation of flight. This is well 

 shown within the limits of a single family in the case of Calasymbolus 

 my ops, a Sphingid with the hindwings large in comparison with 

 the hindwings of Choerocampa, Philampelus, Ellema and others 

 showing extreme cephalisation of flight. In Calasymbolus, the 

 disk of the hindwing is uniformly covered with flat scales, only 

 the basal third of the wing showing long, weak scale-hairs. In 

 Philampelus achemon, only the marginal brown edging is composed 

 of specialised scales, without the presence of scale-hairs, while all 

 the discal and basal portion of the wing is covered with long, 

 rather thickened scale-hairs, in addition to flat scales. Choerocampa 

 tersa shows a similar condition, as also does Ellema bombycoides. 

 The fact that a heavy flyer shows a less specialised scale-covering 

 than a swift flyer is also illustrated among the Sphingidae. Triptogou 

 modesta, a slow, heavy-bodied moth compared with Philampelus, 

 has its forewings covered with long, thickened, two- to three-pointed, 

 rather flattened scale-hairs thickly inserted, but rather assurgent, 

 and not closely appressed to the wing surface. The hindwings 

 bear elongate, single-pointed scale-hairs, and also some scales 

 like those of the forewing, altogether a much more generalised 

 condition of scale development than that of Philampelus, whose 

 forewings are uniformly covered with broad three- to seven- 

 pointed flat scales, becoming a little longer toward the base of the 

 wing." We may here add that experiments on the contents of the scales 

 of Smerinthus ocellata, show that if the hindwings be yellowed by 

 HC1 they afterwards recover their full natural colour ; and 

 it they be then subjected to strong HC1 for an hour or so and 



