Mr. Curtis on Elater noctilucus. 381 



wood away with their mandibles, to obtain the saccharine matter 

 on which they fed ; and after his stock was consumed, he gave 

 them brown sugar, by which means they were kept alive the 

 whole of their voyage, from June to the middle of September. 



Elater noctilucus^ like the rest of the genus, (of which we 

 have in this country between fifty and sixty species,) is enabled by 

 the thoracic process to gain its feet by a spring when laid on its 

 back ; but it has not the muscular power that many of the smaller 

 ones have, and is therefore not able to leap more than three or 

 four times its own length. The brilliant light, which emanates 

 from a convex spot on each side of the thorax, shines forth or is 

 extinguished at the will of the animal. The power of the light, 

 when excited by the breath or by friction, was so great, that car- 

 rying it along the lines of a book I could distinctly read them, 

 and applying it to my watch, I could without difficulty ascertain 

 the hour. 



The insect when roused and in perfect vigour seems to he com- 

 pletely saturated with this luminous secretion, since the back, 

 when the elytra and wings are expanded, has a phosphoric appear- 

 ance, and there is a strong light at the base of the abdomen where 

 the posterior coxae are attached, which being apparent only in 

 some, I thought might be peculiar to one sex, but its absence was 

 more probably caused by the languid state of the animal. The 

 light is far more beautiful in colour, and greater in power, than 

 the mild secretion of the Glow-worm, ( Lampyris noctiluca^) and 

 the substance, if removed from the beetle immediately after death, 

 will remain luminous, like phosphorus, on the object upon which 

 it is placed. 



I have to regret that these Insects arrived at a period when the 

 meetings of the Linnean Society were suspended, and very few 

 Naturalists were in town who could partake of the tropical treat 

 which the exertions and kindness of Mr. Lees had prepared for 

 them ; for the weather becoming suddenly cold they soon shewed 

 symptoms of languor, and died in a few days. 



It is to be hoped that others will be induced to bring these 

 Insects over alive earlier in the season ; for there can be little 

 doubt that they would live through a warm summer in this climate. 



