l894-] ENTOMOLOGICAL NEWS. 317 



It is probably simply the result of a chemical action which produces a 

 phosphorescence. It is produced at one four-hundredth of the cost of 

 energy represented in a candle flame, and is supposed to come from the 

 slow combustion of a material secreted by the nervous organism of the 

 insect. The temperature of the light-giving organs is the same as that of 

 other parts of the body. 



In Prof. Langley's experiments he took the insects, kept them in the 

 dark all the time, and ground the dried substance to powder. In all these 

 cases the application of moisture produced a light, proving the chemical 

 origin of the phenomenon. To produce a light of equal brilliancy artifi- 

 cially would require a temperature of at least 2000°. The most brilliant 

 of the 150 varieties of the animal life capable of producing a light of this 

 character is the " cucujo," the famous firefly of the tropics. Thirty-eight 

 of these yield one candle powder. The natives of Cuba confine them in 

 paper lanterns, and they have been used to take photographs by a two- 

 minute exposure of bromide plates. 



These insects, or beetles, to speak exactly, were used by Prof. Langley 

 in experimenting. They begin life as a grub, and are variously called 

 "skipjacks," or "spring tails." Damp evenings seem to be the most 

 favorable time to observe their habits, as then they shine most brilliantly. 



Nature having produced this most economical light, when in the most 

 ex^gerated instance cannot be made to affect the most delicate ther- 

 mometer, seems to laugh at the feeble efforts of man to follow her plan. 

 It is true that the Geissler tube, a plaything of the laboratory, will produce 

 light, without heat, but it is incapable of practical production. Scientists 

 believe that ere long the subject of the wonderful light, which has been 

 proved to be not unlike the luminous calcium sulphide paint of commerce, 

 will be discovered, with a result as revolutionary in the world of illumina- 

 tion as that caused by electricity. — Boston Journal. 



Identification of Insects (Imagos) for Sabscribers. 



Specimens will be named under the following conditions : 1st, The number of species 

 to be limited to twenty-five for each sending; 2d, The sender to pay all expenses of trans- 

 portation and the insects to become the property of the American Entomological Society • 

 3d, Each specimen must have a number attached so that the identification may be an- 

 nounced accordingly. Exotic species named only by special arrangement with the Editor 

 who should be consulted before specimens are sent. Send a 2 cent stamp with all insects 

 for return of names. Before sending insects for identification, read page 41, Vol. Ill 

 Address all packages to Ento.mological News, Academy Natural Sciences, Logan 

 Square, Philadelphia, Pa. 



Entomological Literature. 



I. The American Naturalist. Philadelphia, October, 1894.— De- 

 scription of a new Pelecinus {^P. brmtneipes'] from Tennessee, W. H. 

 Patton. 



