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70 F. The insects, when undisturbed, seemed anxious 

 to gain the summits of the blades of grass toward 

 evening and at night, and from thence displayed their 

 beauteous insignia by holding up the lower rings of 

 the abdomen. When they had ceased to shine, as 

 well as during the day, they sought the roots of the 

 grass. The luminous matter was carefully inspected 

 by a lens, but not the slightest undulatory motion 

 could be perceived which might connect it with any 

 thing like combustion, and the luminous matter ap- 

 peared incased in a transparent sac. On the 12th of 

 June, at 20 minutes past 7 P. M., excluded from light, 

 it had already kindled up a faint beam : when the insect 

 was exposed to light, it ceased to shine, and appeared 

 annularly translucent in the membrane which covered 

 the luminous belts. At 50 minutes past 9 P. M. it 

 shone exceedingly bright; still, by the most careful 

 inspection, no undulatory movement could be seen, 

 which proves it not to be a languid combustion, and 

 though the light evidently intermits, it does not glow 

 as in aphlogistic exhibitions. While it remained at- 

 tached to a spike of grass, we could easily read a letter 

 by the light it shed, by moving the insect over the 

 lines. About this period, thermometer constantly 

 ranging from 70 to 80 F., the glow-worm shone most 

 vividly, and one was so intense on the road from 

 Oswestry to Ruyton, that a horse started at the 

 gleam, and nearly overthrew its rider. Our observ- 

 ations would certainly prove that the luminous matter 

 is under the control or management of the insect, 

 and we have noticed that the light is kindled up when it 

 moves on the leaf, and its palpi are then employed. We 

 once found five luminous specks, of a minute oval form, 

 in the box which contained our glow-worms : they 

 were evidently secreted by the insect, and might be 



