73 



•elves entirely to the consumption and removal of the excrement of the larger herbiTorous 

 animals. Need we say that they should, on no account, be destroyed ? 



7. LuMiNOTJs Insects (Lampyridcf). 



In the regular order of families of beetles, according to the generally received classifica- 

 tion of Coleoptera, we come to a number of decidedly noxious insects after the Dung-beetles 

 just described ; such for instance as the May-beetles and other leaf-eaters, (Melolonthidce), the 

 Buprestis Borers that perforate the wood of a majority of our trees, 

 F'e- 76. (Fig. 76), and the Spring-back Beetles, (Elateridce), parents of the 



justly dreaded Wire-worms. The first family of common insects that 

 we come to after these, are the Fire-flies — luminous insects of the family 

 La7npi/rid(e. 



In tropical countries the fire-flies bo'ong to two very difierent 

 families of beetles, the Elateridse and the 'lampyridse, but in Canada 

 luminous examples of the former are very rire indeed, though we have 

 myriads of the latter. Our fire-fiies. in the perfect state, are soft flattened beetles, with the 

 head almost entirely concealed under the projecting hood formed by the thorax ; they are 

 generally of pale colours, though sometimes black. They are voracious in their habits ; feed- 

 ing in the larval state, upon earth-worms and soft-bodied insects. The light which they 

 emit proceeds from the extremity of tlie abdomen, and appears, from its fitfnlness, to be un- 

 der the control of the insects. Its origin and composition have long been a matter of doubt. 

 According to Siebold, " the luminous organs of these insects consist of a mass of spherical 

 cells, filled with a fine granular substance, and surrounded by numerous trachean branches. 

 This substance appears, by daylight, of a yellow, sulphur-like aspect. The light produced 

 from these organs, so remarkably rich in trachea;, is undoubtedly the result of a combustion 

 kept up by the air of these vessels. This combustion explains the intermission of the phosphor- 

 escence observed with the brilliant fire-flies, and which coincides, not with the movements of 

 the heart, but with those of inspiration and expiration." 



All our readers are, no doubt, perfectly familiar with the sparkling intermittent light 

 exhibited by fire flies on damp summer evenings. They appear to take especial delight in 

 moisture, frequenting low marshy gi-ounds and river bottoms in myriads, while they but oc- 

 casionally visit tlie drier air of high ground. We have sometimes seen them in tens of thou- 

 sands, nay millions, when driving at night along some sequestered country road bordered by 

 wet, swampy ground, or when taking a nocturnal ramble in search of insects up the valley of 

 the Credit. Brilliant and numerous though our Canadian fire-flies are, they cannot be com- 

 pared— judging from the accounts of naturalists — with the glories of the tropical species. 

 There, besides species similar to ours, they have the huge lantern flies, said to lie two or 

 three inches long, and omitting a most brilliant light and also the largo spring-back 

 beetle (Elater Noctilucus) that gives forth a bright glow from spots on the thorax. Southey 

 thug describes the appearance of these creatures in tropical America: — 



" Soon did night display 

 More wonders than it veiled ; iimumerous tribes 

 From the wood cover swarm' d and darkness made 

 Their beauties visible ; one while they stream'd 

 A bright blue radiance upon flowers that closed 

 Their gorgeous colours from the eye of day ; 

 Now motionle3.s and dark, eluded search, 

 Self-shrouded ; and anon, starring the ^y. 

 Rise like a shower of fire." 



In England they have but one species of luminous insect, well known under the 

 name of ' glow-worm." The females of this insect are long, flat, soft wormlike creatures, 

 quite destitute of wings ; emitting usually a pale steady light from the extremity of the ab- 

 domen. The males, on the other hand po.ssess complete wings and wing covers, and are but 

 feebly luminous. We have taken them in early summer in the long damp grass beside 

 hedge-rows in Lancashire, where their tiny light attracted us from some little distance. 

 They did not, however, appear to be at all common. 



In this country both sexes of the fire-flies are fully winged, and both appear to b« 

 equally luminous. The larvaj also of several species possess the property of emitting light ; 

 bnt of these wc have rarely obt&ined specimens. In 1868 we obtained a remarkabla larva 

 6 



