370 



Marvels of Insect Life* 



they eject a caustic and ill-smelling fluid, with the object of disgusting a pursuer. 

 In the case of the bombardier, this fluid rapidly volatilizes on exposure to the air, 

 and goes off as a bluish vapour. Its emission is accompanied by a cracking sound. 

 Dufour describes the odour as similar to that of nitric acid, and says that litmus 

 paper reddens on being exposed to its fumes. One can imagine the effect produced 

 on its pursuer by such a discharge, which can be repeated. Cooper, quoted bv 

 Stephens, has recorded that one specimen " performed the operation no less than 

 thirteen times in rapid succession " ; and Rolander says it is capable of twentv 



discharges. 



The volatile fluid if brought into contact with the human skin causes 



a burning sensation, and makes a red mark, which afterwards turns brown. 



Mosquitoes and Gnats. 



When a townsman goes into the 

 countr}^ and takes a rest on a flowerv 

 bank, he sometimes gets bitten b\' a 

 gnat. The part of his anatomy selected 

 by the Insect for experimental borings 

 is usually either the ankle, the temples, 

 or the back of the neck. The so-called 

 " bite " of the gnat is a stab from a 

 stiletto, and the instrument being 

 perforated the Insect is able to suck 

 a dro}) of blood through it. The stab 

 itself is nothing — a mere pin-prick, but 

 the Insect appears to inject a minute 

 drop of some liquid, probably for the 

 purpose of thinning the blood and 

 making it flow more freely. But with 

 some temperaments it does more than 

 this---it produces a smarting, burning 

 sensation, and around the puncture the 



Photo by] 



Beautiful Searcher. 



[E. Step, F.L.S. 



One of the prettiest of the ground-beetles, but unfortunately rare 

 in this country. In both grub and perfect stages it preys upon 

 noxious Insects. An allied species on the Continent wages war upon 

 the destructive processionary caterpillars. Twice the natural size. 



flesh may swell up into a large in- 



flamed bump. When there are symp- 

 toms such as these the victim is 

 assured that he has not been bitten by an ordinary common gnat — it must have 

 been a mosquito, such as one reads of in books of foreign travel. No British Insect 

 could be so malignant ! To such a sufferer the statement that the Insect 

 sometimes dies as the result of its indulgence in human blood will be read 

 with satisfaction — it is so like the finale of Goldsmith's Ele^y on the dog who 

 " to gain some private ends, went mad and bit the man." In the result we 

 know on good authority that : — 



" The man recovered of the bite ; 

 The dog it was that died." 

 Even man may have in his blood some microbe that is deadly to blood-sucking 

 flies as well as to dogs. Naturally, we only look at the matter from our own point 



