ANIMAL AND VEGETABLE PHOSPHORI. 125 



into the bodies of luminous animals, in the form of food, anil may 

 be separated from its respective combinations by its luminous 

 orgaus. 



Living luminous Substances* 



These are very numerous, though they have never hitherto been 

 arranged into any distinct classification, or tabular form. They 

 consist chiefly, and almost exclusively, of insects and zoophytes ; 

 molluscous zcorms / though instances are occasionally met with 

 among other worms. Insects furnish nearly a dozen distinct ge. 

 nera, of which almost all the species are luminous. The chief 

 are the lampyris, or glow-worm, and fire. fly tribes; the fulgora, 

 or lantern. fly ; the scolopendra, or centipede; the fausus spoero. 

 cenus; the elater noctilurus, and the cancer fulgens. Among the 

 worm. class the principal are the phloas, or pholas, as it is now 

 generally, buterroneously denominated, the pyrosoma, the medusa 

 phosphorea, the nereis noctiluca, the pennatula, or sea pen, and ra. 

 rious species of the sepia or cuttle-fish. The atmosphere in some 

 parts of Italy appears occasionally to lie on fire, in the evening, from 

 the great quantities of one species of the lampyris that throng toge- 

 ther. A single individual of the South-American fulgora, fixed upon 

 the top of a cane, or other staff, will afford light enough to read by. 

 The streams of light that issue from the elater noctilucus are so 

 strong in the night, that even the smallest print may be read by 

 their lustre. The pyrosoma, when at rest, emits a pale blue 

 lustre ; but when in motion a much stronger light, variegated by 

 all the colours of the rainbow. The phloas secretes a luminous 

 juice, every drop of which illuminates, for a length of time, 

 whatever substance it falls upon, or even touches ; and the animal, 

 after death, may be preserved so as to retain its luminous power 

 for at least a twelvemonth. The noctilucent nereis often illumi- 

 nates, by its numbers, the waters it inhabits, to a very consider* 

 able extent ; and gives so bright a splendour to the waves that, 

 like the atmosphere when lighted up by the lampyris italica, they 

 appear as though they were in a full flame. The organ from which 

 the luminous matter is thrown forth, in these different animals, h 

 of a very different character, and placed in very different parts of 

 the body ; sometimes in the head, sometimes in the tail, sometimes 

 in the antennas, sometimes over the surface generally. 



