272 THE NATURAL HISTORY OF 



Mons. Peron, during hi9 voyage to the South Seas, col- 

 lected a great number of this remarkable genus of animals. 

 In a memoir presented by him to the National Institute of 

 France, in 1809, their singularities are thus expressed. 

 " Their substance seems to be merely a coagulated water ; 

 yet the most important functions of life are exercised in it. 

 Their multiplication is prodigious ; yet we know nothing of 

 the peculiar mode in which it is effected. They are capable 

 of attaining the weight of fifty or sixty pounds, and of be- 

 coming several feet in diameter; yet their nutritive system 

 escapes our eyes. They execute the most rapid and long- 

 continued movements ; yet the details of their muscular 

 system are imperceptible. They have a very active species 

 of respiration, the true seat of which is a mystery. They 

 appear extremely feeble ; yet fish of considerable size form 

 their daily prey, and dissolve in a few moments in their 

 stomach. Many species of them shine in the night like balls 

 of fire, and some sting or benumb the hand that touches 

 them ; yet the principles and agents of both these proper- 

 ties remain to be discovered. If put into fresh water, they 

 die in about half an hour." * 



All the medusa? have a gelatinous body, nearly resembling 

 the cap of a mushroom, which the Abbe Spallanzani de- 

 nominated " Umbella;" but they differ, some in wanting or 

 some in having a mouth ; in the mouth being simple or 

 multiplicious ; in the presence or absence of a production 

 resembling a pedicle ; and in the edges of this pedicle, or 

 of the mouth itself, being furnished with tentacula, or fila- 

 ments, more or less numerous. Some of these animals ex- 

 hibit beautiful colours. They are found in all climates, but 

 more particularly in the Southern Ocean. 



Some of the species have the power of benumbing the 

 hand when touched ; hence the name of sea nettles have 

 been applied to them. The appearance' of many is pe- 



* Zool. Dan. ii. t. 77. 



