510 LUMINOUS INSECTS, 
pillars of Noctua (Polia) occulta to be luminous.! 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 larve 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 * 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* 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, avd which he 
describes as flitting about a thistle, 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.® 
1 Ann. Soc. Ent. de France, i. 424, 8 Silbermann, Fev. Hntom. i. 226. 
5 Rey. Dr. Sutton of Norwich. 4 Travels, 2d ed. 334, 
5 Phil. Trans, 1729, 204, 
® A paper by Richard Chambers, E'sq., in the Magazine of Nat, Hist, (New Series, 
i, 353.), relates several facts observed by the celebrated botanists Mr, James Dickson, 
and Mr, Curtis, author of the Mora Londinensis, 'T. Stothard, Esq., R.A. (who was, 
as before mentioned, a zealous entomologist), his father, Mr. A, Chambers, and 
