THE PHOSPHORESCENCE OP THE SEA. 
285 
they have absorbed during the day ;* that of Brugnatelfi, who 
regards it as the light ingested with the food (!), and penetrat- 
ing to the surface through the vital organs ; and even that of 
Gilbert, who conceives the luminosity of the Noctilucae more 
particularly, to be owing to electric sparks drawn from these 
little creatures by the friction resulting from their passage 
through the water. 
The researches of Spallanzani, Burmeister, and more especially 
those of Macaire, first cast a true light upon the nature of the 
phenomenon under consideration. This investigator had em- 
ployed the insect races as the objects of his researches, and he 
expressed the opinion that the fight emitted by these was the 
result of a slow combustion comparable to that of phosphorus 
exposed to the atmosphere. This conclusion has been com- 
pletely confirmed by the recent researches undertaken by M. 
Matteucci, weighted, as these are, by the application of all the 
resources of modern science and the reputation of the author. 
The fight of the LympyridEe (glow-worms) and Elateridse 
(luminous beetles, commonly known as “ fire-flies ”) is extin- 
guished in a vacuum or in irrespirable gases ; it reappears in 
atmospheric air, and becomes remarkably brilliant in oxygen 
gas. It is emitted from a peculiar substance possessing the 
same properties in the living animal as it does after its decease, 
until completely desiccated; and, lastly, this luminosity is 
accompanied by a disengagement of carbonic acid. These are 
all evidences of a true combustion. j- But does this explana- 
tion, true as regards certain insects, apply also, to those inver- 
tebrates whose habitat is the ocean? Duges and a great 
number of naturalists have thought so ; but it is difficult to 
understand how such a combustion can proceed in submerged 
bodies or in fluids, such as those secreted by the Medusas and 
Pholades. On dissolving the mucosity produced by the former 
in milk, Spallanzani rendered the liquid so luminous that he 
was enabled to read by the fight from the glass vessel in which 
it was contained ; and M. Edwards observed that the secre- 
tions of some Pholades, which he had placed in alcohol, formed 
a luminous stratum at the bottom of the glass jar in which it 
takes place at the surface of some liquids and solids in consequence of a 
change in the refrangibility of the different rays.”' — Graham. 
* That such a phenomenon is not only possible, but actually occurs in con- 
nection with inorganic substances, has been shown by the experiments of 
M. Niepce de St. Victor, as detailed in our last number, p. 268, — “ Actinism.” 
t The experiments upon which the author of this paper has based his 
observations on the luminosity of insects are at variance with those of Pro- 
fessor Koelliker, an account of which appeared in the Microscopical J ournal, 
(p. 166) of 1858. M. de Quatrefages has had no opportunity of reading those 
observations, but requested us to append an abstract of them to his paper, 
which we have done in a note at the conclusion of this article. — Ed. 
