Oct. 1, 1S67.] 



HARDWICKE'S SCIENCE-GOSSIP. 



227 



in having larger wing-pads. It is still active, and 

 as much of a gourmand as ever. When the insect 

 is about to assume the pupa state, it moults its skin. 

 The body having outgrown the larva skin, by a 

 strong muscular elFort a rent opens along the back 

 of the thorax, and the insect, having fastened its 

 claws into some object at the bottom of the pool, 

 the pupa gradually works its way out of the larva- 

 skin. It is now considerably larger than before. 

 Immediately after this tedious operation, its body 

 is soft, but the crust soon hardens. This change, 

 with most species, probably occurs early in summer. 

 When about to change into the adult fly, the 

 pupa climbs up some plant near the surface of the 

 water. Again its back yawns wide open, and from 

 the rent our Dragon-fly slowly emerges. Eor an 

 hour or more, it remains torpid and listless, with 

 its flabby, soft wings remaining motionless. The 

 fluids leave the surface, the crust hardens and dries, 

 rich and varied tints appear, and our Dragon-fly 

 rises into its new world of light and sunshine a 

 gorgeous but repulsive being. Tennyson thus 

 describes these changes in "The Two Voices": — 



To-day I saw the Dragon-fly 

 Come from the wells where hs did lie. 

 An inner impulse rent the veil 

 Of his old husk : from head to tail 

 Came out clear plates of sapphire mail. 

 He dried his wings ; like gauze they grew; 

 Through crofts and pastures wet with dew 

 A living flash of light he flew. 



The largest of our Dragon-flies are the " Devil's 

 Darning-needles," iEscima heros and grandis, seen 

 hawking about our gardens till dusk. They fre- 

 quently enter houses, carrying dismay and terror 

 among the children. The hind-body is long and 

 cylindrical, and gaily coloured with bright green 

 and bluish bauds and spots. 



One of our most common Dragon-flies is Diplax 

 rubicundula, the ruby Dragon-fly, which is yellowish 

 red. It is seen everywhere flying over pools, and 

 also frequents dry sunny woods and glades. Another 

 common form is Diplax berenice of Drury. It is 

 black, the head blue in front, spotted with yellow, 

 while the thorax and abdomen is striped with 

 yellow. There are fewer stripes on the body of the 

 male, which has only four large yellow spots on each 

 side of the abdomen. Still another pretty species is 

 Diplax elisa of Dr. Hagen. It is black, with the 

 head yellowish and with greenish yellow spots on 

 the sides of the thorax aud base of the abdomen. 

 There are three dusky spots on the front edge of 

 each wing and a large cloud at the base of the hind 

 pair towards the hind angles of the wing. 



Rather a rare form, and of much smaller stature 

 is the Nannophya bella of Uhler. It was first 

 detected in Baltimore, and we afterwards found it 

 not unfrequently by a pond in Maine. Its abdomen 

 is unusually short, and the reticulations of the 

 wings are large and simple. The female is black, 



while the male is frosted over with a whitish 

 powder. Many more species of this family are 

 found in this country, and for descriptions of them 

 we would refer the reader to Dr. Hagen's Synopsis 

 of the Neuroptera of North America. 



The Libellulidrc, or family of Dragon-flies, and 

 the Epheinerida), or May-flies, are the most charac- 

 teristic of the Neuroptera, or veiny-winged insects. 

 This group is a most interesting one to the system- 

 atise as it is composed of so many heterogeneous 

 forms which it is almost impossible to classify in 

 our rigid and at present necessarily artificial 

 systems. We divide them into families and sub- 

 families, genera and sub-genera, species and varie- 

 ties, but there is an endless shifting of characters 

 in these groups. The different groups would seem 

 well limited after studying certain forms, when to 

 the systematist's sorrow here comes a creature, 

 perhaps mimicking an ant, or aphis, or other sort of 

 bug, or even a butterfly, and for which they would be 

 readily mistaken by the uninitiated. Bibliographers 

 have gone mad over books that could not be classified. 

 Imagine the despair of an insect-hunter and ento- 

 mophile, as he sits down to his box of dried neu- 

 roptera. He seeks for a true neuropter in the 

 white ant before him, but its very form and habits 

 summons up a swarm of true ants ; and then the 

 little wingless book-louse (Atropos), scampering 

 irreverently over the musty pages of his Systema 

 JValu/ve, reminds him of that closest friend of man 

 — Pediculus vestimenti. Again, his studies lead 

 him to that gorgeous inhabitant of the Mediter- 

 ranean shores, the butterfly-like Ascalaphus, with 

 its gorgeous wings and slender knobbed antennae, so 

 much like those of butterflies, and visions of these 

 beautiful insects fill his mind's eye ; or sundry dun- 

 coloured caddis flies, modest, delicate neuroptera, 

 with finely fringed wings and slender feelers, create 

 doubts as to whether they are not really allies of 

 the clothes moth, so close is the resemblance. 



Thus the student is constantly led astray by the 

 wanton freaks Nature plays, and becomes sceptical 

 as regards the truth of a natural system, though 

 there is one to be discovered ; and at last disgusted 

 with the stiff and arbitrary systems of our books, — 

 a disgust we confess most wholesome, if it only lead 

 him into a closer communion with nature. The 

 sooner one leaves those maternal apron-strings, — 

 books, — and learns to identify himself with nature, 

 and thus goes out of himself to affiliate with the 

 spirit of the scene or object before him, — or, in 

 other words, cultivates habits of the closest obser- 

 vation and most patient reflection, — be he painter or 

 poet, philosopher or an insect-hunter of low degree, 

 he will gain an intellectual strength and power of 

 interpreting nature, that is the gift of true genius. 



[Although originally written for the American 

 Naturalist, there is much in this chapter which is 

 of interest also to the British student.] 



