PHOSPHORESCENCE OF FIRE-FLIES. 
Ill 
seum. And at Content, in the latter part of July, I 
found in fresh-turned earth a larva of a Lampyris, 
small and lengthened : the abdomen, like that of the 
European Glow-worm, was furnished with a retractile 
brush of divergent filaments, ordinarily concealed; 
but having no lens with me I could not examine it 
particularly. 
Mr. Hill has favoured me with the following inte- 
resting speculations on the phosphorescence of these 
insects ; particularly on the Pyrophorus noctilucus, 
which he indicates by the term ‘‘ Eire-fly.” 
“ Humboldt states that the larva of the Eire-fly 
feeds on the roots of the sugar-cane, and proves de- 
structive to that plant in the West India Islands. 
This remark was no doubt made on information 
derived from Spanish planters ; and relied on, be- 
cause consistent with the known habits of the larvae 
of European ElateridcB , — particularly the well-known 
wire-worm, which devours the roots of vegetables, 
and does considerable damage to corn-fields. No 
one can have looked upon a stretch of canes in some 
rich and teeming soil in one of our serene nights, and 
seen the numerous luminous insects shooting athwart 
the gloom like meteors, or spangling the wide land- 
scape as with a thousand stars, without being struck 
with the relation which subsists between the preva- 
lence of phosphorescent insects, and the growth of 
a plant, like the sugar-cane, which depends on the 
presence of an unusual degree of phosphates in the soil. 
The fact is, that the peculiar economy of these insects 
with respect to their phosphorescence is carried on by 
the aid of vegetable food in which phosphorus is 
