510 LUMINOUS INSECTS. 



pillars of Noctua (Polui) occulta to be luminous. 1 This observation as to 

 another species has been confirmed by Dr. Boisduval," who one evening of 

 the hot days of June found on the stems of grass caterpillars which spread 

 a phosphorescent light, and which he thought were those of Mamestra ole- 

 racea, though they seemed larger than common ; and whether from want 

 of care, or that their luminosity depended on disease, none of them assumed 

 the pupa state. They certainly, he says, were not the larva? of Polia 

 occulta? 



But besides the insects here enumerated, others may be luminous which 

 have not hitherto been suspected of being so. This seems proved by the 

 following fact. A learned friend 3 has informed me, that when he was 

 curate of Ickleton, Cambridgeshire, in 1780, a farmer of that place of the 

 name of Simpringham brought to him a mole-cricket (Gryllotalpa vulgaris 

 Latr.) and told him that one of his people, seeing a Jack-o'-lantern, pursued 

 it and knocked it down, when it proved to be this insect, and the identical 

 specimen shown to him. 



This singular fact, while it renders it probable that some insects are 

 luminous which no one has imagined to be so, seems to afford a clue to 

 the, at least, partial explanation of the very obscure subject of ignes fatui, 

 and to show that there is considerable ground for the opinion long ago 

 maintained by Ray and Willughby, that the majority of these supposed 

 meteors are no other than luminous insects. That the large varying lam- 

 bent flames, mentioned by Beccaria to be very common in some parts of 

 Italy, and the luminous globes seen by Dr. Shaw 4 cannot be thus ex- 

 plained, is obvious. These were probably electrical phenomena : certainly 

 not explosions of phosphuretted hydrogen, as has been suggested by some, 

 which must necessarily have been momentary. But that the ignis fatuus 

 mentioned by Derham as having been seen by himself, and which he 

 describes as flitting about a thistle 5 , was, though he seems of a different 

 opinion, no other than some luminous insect, I have little doubt. Mr. 

 Sheppard informs me that, travelling one night between Stamford and 

 Grantham on the top of the stage, he observed for more than ten minutes 

 a very large ignis fatuus in the low marshy grounds, which had every 

 appearance of being an insect. The wind was very high : consequently, 

 had it been a vapour it must have been carried forward in a direct 

 line ; but this was not the case. It had the same motions as a Tipula, 

 flying upwards and downwards, backwards and forwards, sometimes ap- 

 pearing as settled, and sometimes as hovering in the air. Whatever be 

 the true nature of these meteors, of which so much is said and so little 

 known, it is singular how few modern instances of their having been ob- 

 served are on record. Dr. Darwin declares, that though in the course of a 

 long life he had been out in the night, and in the places where they are said 

 to appear, times without number, he had never seen any thing of the 

 kind : and from the silence of other philosophers of our own times, it 

 should seem that their experience is similar. 6 



1 Ann. Soc. Ent. de France, i. 424. 2 Silbermann, Rev. Entom. i. 226. 



3 Kev. Dr. Sutton of Norwich. * Travels, 2d ed. 334, 



5 Phil Trans. 1729, 204. 



6 A paper by Richard Chambers, Esq., in the Magazine of Nat. Hist. (Xew Series, 

 i. 353.), relates several facts observed by the celebrated botanists Mr, James Dickson, 

 and Mr. Curtis, author of the Flora Londinensis, T. Stothard, Esq., R.A. (who was, 

 as before mentioned, a zealous entomologist), his father, Mr. A. Chambers, and 



