320 COMMON OBJECTS OF THE SHORE. 



and is carried off for food ; while the lamps which 

 shine from countless Medusae help the fish to 

 chase his living prey. Nor have the tribes of 

 jelly-fish performed all their part in creation when 

 they have lighted up the darkness, and in their 

 turn served as food to other tribes of animals. 

 " Possibly," says Professor Jones, " the sea itself 

 is fitted by their agency to be the residence of 

 beings that otherwise would perish. Not the 

 least striking circumstance in the history of the 

 Khizostoma (a genus of large jelly-fishes), is its 

 prodigious power of producing, from the surface 

 of its body, quantities of mucus or thick slime, 

 which is of course mixed up with the surrounding 

 water. When this material is furnished, is even 

 yet a question ; but so copious is the supply, that 

 if a specimen be placed alive in a large vessel 

 filled with water, in a little time the whole is 

 rendered thick and viscid, so that the Rhizostoma 

 would perish speedily from the accumulation of its 

 own secretions. You change the water, but in 

 vain, still the abundant mucus is poured forth, nor 

 does it cease as long as life remains. But if a 

 single specimen afford such quantities of viscid 

 matter, we shall conceive when we reflect upon 

 the countless multitude of Acalephse, spread 

 through every sea, that their united agency must 

 cause important changes in the water around them, 

 filling it with animal substance, upon which in- 

 numerable races may be fed, a kind of nutriment 

 adapted to the feeble mouths of new-hatched 

 spawn, or ocean's tenderest progeny." 



The whole tribe of jelly-fishes are included 

 under the name of Acalephse, the Greek word for 

 a nettle, and they are commonly called Sea-nettles, 



