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 " Fire-fly." 



" Humboldt states that the larva of the Fire-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 ^/a^eric?ce, — 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 o^ 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 



