OF FULGORA CAN DELARI A. 107 



name : yet that property has never been noticed in them, but 

 frequently in Lampyris. In the last- mentioned genus, and in 

 the phosphorescent Elateres, the luminous parts have a pale 

 sulphur colour quite different from that of the rest of the body ; 

 whereas the snout of Fulgora never shows the like peculiarity. 

 Von Sack, in his " Voyage to Surinam," mentions three dif- 

 ferent species of insects there, which are called fire-flies. His 

 description of F. laternaria, or the lantern-carrier, is probably 

 copied from Merian. He adds : " On putting two of them in 

 a glass, a common print may easily be read by it. It seems, 

 that the real species is principally found in the mountainous 

 parts of Guiana, and only appears there in the rainy season. 

 I have not been able to procure a living one." He then 

 describes Elater and Lampyris. Lacordaire observes, that at 

 Caj eniw, where the Fulgorce are very rare, some of the inha- 

 bit !i .y that they emit a very brilliant light; others absolutely 

 deny this fact. Having never seen the insects alive, he was 

 obliged to remain in doubt. Spix and Martius often saw 

 F. laternaria alive, but never observed any phosphorescence 

 in it. The Indians call it Jacarenam-boya, or the crocodile- 

 snake, and say that it inflicts wounds, and is extremely 

 venomous. It flies swiftly, describing large circles, and appears 

 chiefly in the evening on the sandy islands of the Amazon 

 river. Its evening flight is an argument very much in favour 

 of its being luminous ; but even allowing the luminosity, still 

 it has a snout very different in shape from those of F. cande- 

 laria, and the rest of the species of the Old World; and there 

 is not the slightest authority for maintaining that these latter 

 are luminous. As for common consent proving their luminosity, 

 common sense proves that their luminosity would have been 

 observed and talked of had it existed. It would be as rational 

 to maintain that every Elater is luminous. I was astonished 

 when I heard the author of the Letters of Rusticus talking 

 about common consent ; he told us that the weasel sucked blood 

 by common consent; and that if a tail had been denied him by 

 his first historian, he would be tailless by common consent. 

 Common consent on subjects, means that the human mind has 

 never thought about them till roused and freed from bondage 

 by peculiar circumstances. Kcempfer, in his History of Japan, 

 tells us, that " the glow-worms {Cicindelce) settle on some " 

 trees, like a fiery cloud, with this surprising circumstance, that 



