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the ova. They continued luminous for some time, 

 the light was of a different tint of colour, which may 

 be accounted for on the simple intervention of atmo- 

 spheric air in one case, and the transparent film of the 

 membrane which enveloped it, in the other. We 

 always observed that our glow-worms concealed them- 

 selves during the day among the roots of the grass, 

 and that they feed only at night seems very evident. 

 On holding the candle near, they do not withdraw 

 their shining immediately, but it gradually attenuates. 

 We let one fall on a cold slab of marble, but it still 

 shone brilliantly the insect, doubtless, having the 

 power of sustaining a superior temperature. 



The physical strength of the glow-worm seems not in- 

 considerable : we had about two dozen in a box, supplied 

 with grass and moss : the lid was loosely tacked down, 

 and seemed secure enough for them : in this, however, 

 it appears we were mistaken ; for, on returning home 

 one night, the lid of the box had been detached, and 

 our glow-worms scattered on the carpet of the room, 

 which appeared powdered with diamonds. We must 

 acknowledge here our obligations to T. N. Parker, Esq. 

 of Sweeney Hall, through whose kindness we were 

 abundantly supplied with these insects for the pur- 

 pose of experiment, his servant having, by his desire, 

 collected them for us. 



After the luminous sacs were detached from the 

 glow-worm, the light in the penultimate and ante- 

 penultimate rings was absorbed, with the exception of 

 the two luminous points on the anal sac. But by 

 proper pressure, the luminous spherulae might be de- 

 tached entire, and if not crushed or lacerated, would 

 continue to evolve light after their detachment from 

 the nidus in which they were imbedded. The luminous 

 globules are altogether independent of the inter- 



