NATURAL HISTORY. 



639 



it is so likewise in other parts of 

 the world. Many observers ap- 

 pear to have mistaken this species 

 for the nereis noctiluca, which was 

 very natural, as they were prepos- 

 sessed with the idea of the fre- 

 quent existence of the one, and 

 had no knowledge of the other. 

 Some navigators have actually de- 

 scribed this species of medusa, 

 without being aware of its nature. 

 Mr. Bajon, during his voyage from 

 France to Cayenne, collected 

 many luminous points in the sea, 

 which, he says, when examined 

 by a lens, were found to be mi- 

 nute spheres. They disappeared 

 in the air, Doctor le Roy, in 

 sailing from Naples to France, ob- 

 served the sparkling appearance of 

 the sea, which is usually produced 

 by the medusa scintillans. By fil- 

 tering the water, he separated lu- 

 minous particles from it, which he 

 preserved in spirits of wine : they 

 were, he says, like the head of a 

 pin, and did not at all resemble 

 the nereis noctiluca, described by 

 Viannelli; their colour approached 

 a yellow brown, and their sub- 

 stance was extremely tender, and 

 fragile. Notwithstanding this stri- 

 king resemblance to the medusa 

 scintillans, leRoy, in consequence 

 of a preconceived theory, did not 

 suppose what hesawwereanimals, 

 but particles of an oily or bitu- 

 minous nature. 



The minute globules seen by 

 Mr. Langstaft'in the Indian ocean, 

 were, I think, in all probability, 

 the scintillatingspecies of medusa ; 

 and on my showing him some of 

 these animals I have preserved in 

 spirits, he entertained the same 

 opinion. 



Professor Mitchell, of New 



York, found the luminous ap- 

 pearance on the coast of America 

 to be occasioned by minute ani- 

 mals, that from his description 

 plainly belonged to this species of 

 medusa, notwithstanding which, 

 he supposed them to be a number 

 of the nereis noctiluca. 



The luminous animalcule dis- 

 covered by Forster off the Capeof 

 Good Hope, in his voyage round 

 the world, bears so strong a re- 

 semblance to the medusa scintil- 

 lans, that I am much disposed to 

 believe them the same. He de- 

 scribes his animalcule as being a 

 little gelatinous globule, less than 

 the head of a pin ; transparent, 

 but a little brownish in its colour; 

 and of so soft a texture that it was 

 destroyed by the slightest touch. 

 On being highly magnified, he 

 perceived on one side a depression, 

 in which there was a tube that 

 passed into the body, and commu- 

 nicated with four or five intestinal 

 sacs. The pencil drawings he 

 made on the spot are in the pos- 

 session of sir Joseph Banks.— 

 By comparing these with the re- 

 presentations of the medusa scin- 

 tillans, and some of this species 

 rendered visible, by being a long 

 time preserved in spirits, which 

 I have laid before this learned So- 

 ciety, it will be found, that the 

 only difference between Forster's 

 animalcule and the medusa scin- 

 tillans, is in the appearance of the 

 opake parts, shown in the micro- 

 scopic views. 



Many writers have ascribed the 

 light of the sea to other causes 

 than luminous animals. Martin 

 supposed it to be occasioned by 

 putrefaction:Silberschlag believed 

 it to be phosphoric ; professor J. 



