128 THE INHABITANTS OF THE SEA. 



aid of the transparency, a number of little, elongated, narrow 

 bodies (viscera), which also participated in a high degree in the 

 possession of the phosphoric light." 



In the Pholades or Lithodomes, that bore their dwellings in 

 the hard stone, as other shell-fish do in the loose sands, the 

 whole mass of the body is permeated with light. Pliny gives 

 us a short but animated description of the phenomenon in the 

 edible date-shell of the Mediterranean (PJwlas dactylus) : — 



" It is in the nature of the pholades to shine in the darkness 

 with their own light, which is the more intense as the animal is 

 more juicy. While eating them, they shine in the mouth and 

 on the hands, nay, even the drops falling from them upon the 

 ground continue to emit light, a sure proof that the luminosity 

 we admire in them is associated with their juice." Milne-Edwards 

 found this observation perfectly correct, for wishing to place 

 some living pholades in alcohol, he saw a luminous matter exude 

 from their bodies, which on account of its weight sank in the 

 liquid, covering the bottom of the vessel, and there forming a 

 deposit as shining as when it was in contact with the air. 



Several kinds of fishes likewise possess the luminous faculty. 



The sun-fish, that strange deformity, emits a phosphoric gleam ; 



and a species of Gurnard (Triglot, lucerna is 



said to sparkle in the night, so as to form fiery 



streams through the water. 



With regard to the luminosity of the larger 

 marine animals, Ermann, however, remarks 

 that he so often saw small luminous Crustacea 

 in the abdominal cavity of the transparent 

 Saljpa pinnata, that it may well be asked 

 shore sun-Fish. whether the phosphorescence of the larger 

 creatures is not in reality owing to that of 

 their smaller companions. 



According to Mr. Bennett, " Whaling Voyage round the Globe," 

 a species of shark first discovered by himself is distinguished 

 by an uncommonly strong emission of light. When the specimen, 

 taken at night, was removed into a dark apartment, it afforded 

 a very interesting spectacle. The entire inferior surface of the 

 body and head emitted a vivid and greenish phosphorescent 

 gleam, imparting to the creature by its own light a truly ghastly 

 and terrific appearance. The luminous effect was constant, and 



