JELLY-FISHES. 317 



towards the margin, when we see them slip into the mar- 

 ginal canal from the several openings of the radiating 

 canals. 



This is a very simple and rudimentary blood-system. 

 There is here no heart with its pulsations, no proper 

 arteries or veins, no lungs for oxygenation ; but the pro-, 

 ducts of digestion are themselves thus circulated through 

 the system. And this brings me back to the central point, 

 whence you see depending the curious organ I spoke of. 

 A long cylinder of highly movable and evidently sensitive 

 flesh hangs down from the middle of the roof exactly like 

 the clapper of a bell; and, as if to add to the resem- 

 blance, this same clapper is suspended by a narrow cord, 

 and is terminated by a knob. 



Sometimes this whole organ is allowed to hang about as 

 low as the edge of the bell ; then it gradually lengthens to 

 twice, thrice, nay to five times that length; the tongue 

 lolling out of the mouth to a most uncouth distance, and 

 even the suspending cord (as I presume to term the at- 

 tenuated basal portion) reaching far beyond the margin ; 

 then, on a sudden, like the tentacles, the tongue is con- 

 tracted, thrown into wrinkles, curled into curves, and the 

 whole is sheltered within the concavity; presently, how- 

 ever, to loll out again. 



This proboscis-like organ is called the peduncle, and its 

 office is that of a stomach, of which the knob at the end is 

 the mouth, having a terminal orifice with four minute lips. 

 The flexible substance and rapid motions of this peduncle 

 are suited to enable it to seize small passing animals that 

 constitute its prey ; and I have seen the Sarsia in confine- 

 ment seize with the mouth, and swallow, a newly-hatched 

 fish, notwithstanding the activity of the latter. For hours 

 afterwards, the little green-eyed fry was visible, the engulf- 

 ment being a very slow process ; but the Medusa never let 

 go its hold ; and gradually the tiny fish was sucked into 

 the interior, and passed up the cavity of the peduncle, 



