THE DRAGON-FLY. 489 



at different 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 slight- 

 est 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 un- 

 touched. 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 flavored, 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 

 Ty8i, and to M. de Quatrefages' "Rambles of a Naturalist," Vol. II. 



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

 Libellulidae, 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 DRAGON-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 



