THE JELLY-FISH 1827 



pass between the four under lobes the stomach 

 and the digested matters pass into them to nourish the 

 creature. Around the disk or umbrella, and outside 

 the circular tube, is the fringe of hairs which have, 

 to a certain extent, to do with the capture of prey. 

 Each consists of a filmy substance, in which are fixed 

 thread-cells, not very unlike those of the sea-anemone, 

 but they have longer barbs and sharper thorns 

 stretching out from them. Any violence or irritation 

 causes the thread to shoot forth and to injure. The 

 rest of the body of the Medusa is covered with an ex- 

 cessively thin skin, which has movable cilia upon it. 

 It is supposed, and with some reason for nervous 

 threads and bodies have been found on the disk, 

 close to the gritty bodies especially that these last 

 are eyes, or ears, or both. The nerves supply the 

 muscles that move the umbrella, and cause it to ex- 

 pand and contract, and the muscles are remarkable, 

 for some are not simple contracting fibres all made 

 of one piece, as in the Anemone tribe. 



The jelly-fish, when in full vigor and weighing 

 many pounds, must catch and eat much, and the man- 

 ner in which this is done is by no means perfectly 

 understood. The food is digested, and the results are 

 taken from the stomach into the numerous tubes in 

 the body, where they nourish the tissues. The move- 

 ments of the animal and its extremely delicate mem- 

 branes enable much water to come in contact with 

 it, and it breathes by that means, for there are no 

 special gills or lungs. 



The four round spots on the top of the body, 

 sometimes white and sometimes red in color, are 



C VOL. IV. 



