30 M. Pt'tei'S on the Light of Lampyris Jtalica. 



and of heat, but which, in the absence of one of these excit- 

 ants, manifests no sign of activity or life, and can be preserved 

 thus for ages, although the duration of its real life may not 

 exceed perhaps a few weeks. 



M. Doyere has also given a detailed and excellent account 

 of the anatomy of these animalculse, including, especially, the 

 nervous and muscular systems; and his work is illustrated 

 with beautiful and exact figures.* 



On the Light of Lampyris Italica. By M. W. Peters. 



The Lampyres have been the subject of a great number of researches 

 in reference to their luminous organ; but in regard to the Lampyris 

 Italica, we scarcely possess more than the observations of Carrara, ac- 

 cording to whom this species is provided witli a particular aerial sac, 

 which, proceeding from the mouth, conducts the air to the luminous 

 organ. This particular apparatus ought to be the cause of the differ- 

 ences in the luminous state, since the species of the North of Europe 

 diffuse a continuous, equal, and tranquil light, while that of the Italian 

 species is emitted in sparks. " It is on account of this difference," says 

 M. Peters, " that I had a great desire to find an opportunity of exa- 

 mining the last-mentioned animal. This I at last obtained, during a long 

 stay at Nice, and I did not allow it to escape, in the hope that with a 

 good microscope I should succeed in discovering something positive, both 

 respecting the structure of the phosphorescent part itself, and its relations 

 with the other organs. 



From the middle of May till the middle of the month of July, when 

 walking in the vicinity of Nice after sunset, one is surprised at the 

 curious spectacle then presented by the millions of small scintillating 

 lights creeping about in every direction, sometimes illuminating the 

 point of a rock — sometimes lighting a deep cavity — sometimes suddenly 

 producing, as with a magician's wand, a brilliant illumination on the 

 dark trunks of the olive trees, — a scene which, continually shifting and 

 changing, is of the greatest interest. This appearance is renewed every 

 evening ; but it appears to me to be the more brilliant the greater the 

 degree of humidity in the air. The interval between the scintillations is 

 variable, — sometimes longer — sometimes shorter ; and if one of these 

 animals be examined while it is in a phosphorescent state, it is soon 

 seen that the luminosity is intermittent, and that it only appears when 



• Vide Aimales des Sciences Naturelles, 2d Series, 0th year, tome xiv. 

 p. 269 ; tome xvii. &c. p. 193 ; tome xviii. p. 54. Microscopical Journal, vol. 

 ii., No. 20, p. 251. 



