THE DKAGON-FLY. 489 



points where the stones were on the surface ; for, like other species, the Termites of 

 La Rochelle always work under cover wherever it is possible for them to do so. It is 

 generally only by incessant vigilance that we can trace the course of their devastations 

 and prevent their ravages. 



At the time of M. Audoin's visit, a curious proof was accidentally obtained of the 

 mischief which this insect silently accomplishes. One day it was discovered that the 

 archives of the department were almost totally destroyed, and that without the slightest 

 external trace of any damage. The Termites had reached the boxes in which these 

 documents were preserved by mining the wainscoting, and they had then leisurely set to 

 work to devour these administrative records, carefully respecting the upper sheets and the 

 margin of each leaf, so that a box which was only filled by a mass of rubbish seemed to 

 enclose a file of papers in perfect order. 



The hardest woods are attacked in the same manner. I saw on one of the staircases 

 an oak post, in which one of the clerks had buried his hand up to the wrist in grasping at 

 it for support, as his foot accidentally slipped. The interior of the post was entirely 

 formed of empty cells, the substance of which could be scraped away like dust, while the 

 layer that had been left untouched by the Termites was not thicker than a sheet of 

 paper." 



It is most probable that these insects had been imported from some vessel, as they 

 have attacked two opposite ends of the same town, the centre being at present untouched. 

 M. de Quatrefages tried many experiments on these insects with the view of discovering 

 some method of destroying them, and came to the conclusion that if chlorine could be 

 injected in sufficient quantities, it would in time have the desired result. 



One good quality is, however, attributable to the Termite. The insect is eatable, and 

 even by Europeans is pronounced to be peculiarly delicate and well flavoured, something 

 like sweetened cream. The Termites are prepared for the table by various methods, some 

 persons pounding them so as to form them into a kind of soft paste, while others roast 

 them like coffee beans or chestnuts. 



For further information respecting these wonderful insects, the reader is referred 

 to Smeathman's elaborate investigations recorded in the Philosophical Transactions for 

 1781, and to M. de Quatrefages' "Eambles of a Naturalist," Vol. II. 



Passing by, for the present, several families of the Neuroptera, we come to the 

 Libellulidse, or Dragon-flies. These insects are very familiar to us by means of the 

 numerous Dragon-flies which haunt our river sides, and which are known to the rustics 

 by the very inappropriate name of Horse-stingers, they possessing no sting and never 

 meddling with horses or any other vertebrate animal. The name of DKAGON-FLY, on the 

 contrary, is perfectly appropriate, as these insects are, indeed, the dragons of the air, far 

 more voracious and active than even the fabled dragons of antiquity. 



Even in their preliminary stages the Dragon-flies preserve their predatory habits, and 

 for that purpose are armed in a most remarkable manner. During the larval and pupal 

 states the Dragon-fly is an inhabitant of the water, and may be found in most of our 

 streams, usually haunting the muddy banks, and propelling itself along by an 

 apparatus as efficacious as it is simple, and exactly analogous to the mode by which the 

 nautilus forces itself through the water. The respiration is carried on by means of the 

 oxygen which is extracted from the water ; and the needful supply of liquid is allowed to 

 pass into and out of the body through a large aperture at the end of the tail. On taking 

 one of these creatures from the water the extremity of the tail seems to be pyramidal, but 

 on examination will be seen to consist of several pointed flakes which can be separated 

 and then disclose the aperture above mentioned. 



By means of this apparatus, water is admitted into the body, and, after giving up its 

 oxygen, is violently expelled, thereby forcing the insect forward with a velocity propor- 

 tioned to the power of the stroke. If one of these creatures be put into a glass vessel, it 

 appears at first to move by simple volition ; but if a little sand be allowed to settle at the 

 bottom, the disturbance caused among the grains by the ejected water will show the 

 mode of progression. If the larva be allowed to take in the water, and then suddenly 



