MOTIONS OF INSECTS. 473 



vures are diverging rays, which issue either from a basal area or from the 

 base itself, and terminate in the exterior margin. The wings of many 

 male butterflies, hawk-moths, and moths, are distinguished by a remarkable 

 apparatus, noticed by De Geer, and since by many other naturalists *, for 

 keeping them steady and underanged in their flight. The upper wings, on 

 their under side near their base, have a minute process, bent into a hook 

 (hanms), and covered with hairs and scales. In this hook one or more 

 bristles (tendo), attached to the base of the under wing, have their play. 

 When the fly unfolds its wings, the hook does not quit its hold of the 

 bristle, which moves to and fro in it as they expand or close. The females, 

 which seldom fly far, often have the bristles, but never the hook. The 

 hairy tails of some insects (Sesia) belonging to the hawk-moth tribe are 

 expanded when they fly, so as to form a kind of rudder, which enables 

 them to steer their course with more certainty. 



The insects of this and every other order, except the Coleoptera, fly 

 with their bodies in a horizontal position, or nearly so. As their wings 

 are usually so ample, we need not wonder that the Lepidoptera are ex- 

 cellent fliers. Indeed they seem to flit untired from flower to flower, and 

 from field to field ; impelled at one while by hunger, and at another by 

 love or maternal solicitude. The distance to which some males will' fly is 

 astonishing. That of one of the silk-worm moths (Attacus Paphia) is 

 stated to travel sometimes more than a hundred miles in this way. 2 Our 

 most beautiful butterfly, the purple emperor (Apatura Iris), when he makes 

 his first appearance, fixes his throne on the summit of some lofty oak, from 

 whence in sunny days, unattended by his empress, who does not fly, he takes 

 his excursions. Launching into the air from one of the highest twigs, he 

 mounts often to so great a height as to become invisible. When the sun 

 is at the meridian his loftiest flights take place ; and about four in the 

 afternoon he resumes his station of repose. 3 The large bodies of hawk- 

 moths (Sphinx F.) are carried by wings remarkably strong both as to 

 nervures and texture, and their flight is proportionally rapid and direct. 

 That of butterflies is by dipping and rising alternately, so as to form a 

 zigzag line with vertical angles, which the animal often describes with a 

 skipping motion, so that each zigzag consists of smaller ones. This doubt- 

 less renders it more difficult for the birds to take them as they fly ; and 

 thus the male, when paired, often flits away with the female. 



Amongst the neuropterous tribes the most conspicuous insects are the 

 dragon-flies (Libellitlina), which their metamorphosis, habits, mode of 

 life, and characters considered form a distinct natural order of them- 

 selves. Their four wings, which are nearly equal in size, are a complete 

 and beautiful piece of net-work, resembling the finest lace, the meshes of 

 which are usually filled by a pure, transparent, glassy membrane. In two 



1 De Geer, i. 173. t. x. f. 4. Linn. Trans, i. 135. 



2 Linn. Trans, vii. 40. 



3 Haworth, Lepidopt. Brit. i. 19. Mr. Hewitson, in an interesting notice of this 

 species, informs us that at Kissengen in Bavaria, where he had an opportunity of ob- 

 serving its habits in June and July, A 839, after long and rapid flights in the out- 

 skirts of a neighbouring forest, they would enter its most shady recesses to cool 

 themselves, and lap the moisture from any puddles of water (preferring the most 

 filthy) with their long trunks ; and were so 'eager in this occupation that he has had 

 seven under a small flat net at once, and could even take them readily with his finger 

 and thumb. (Entomologist, June, 1842, p. 324.) 



