156 



THE FOOD OF ANIMALS 



Fig. 410. Beroe 



In another common type, Beroe (fig. 410), there are no fishing- 

 lines, but the body is shaped like an elongated pointed cap, the 

 wide opening of which is to be regarded as a mouth. Some of 

 the species are of large size, and swimming is 

 largely effected by the alternate contraction and 

 relaxation of the walls of the body. The prey 

 consists to a great extent of other sorts of comb- 

 jellies, and there is small chance of escape for any 

 of these which are so unfortunate as to be engulfed 

 within the capacious central cavity of this vora- 

 cious cap, provided as it is with hooks. 



SEA-ANEMONES AND TYPICAL CORALS 

 (ANTHOZOA) 



A brief description of a Sea-Anemone has 

 elsewhere been given as illustrative of the struc- 

 ture of this class (see vol. i, p. 473). We are 

 here concerned with the capture of prey, and 

 at first sight a fixed animal, which resembles 

 when extended a brilliantly -coloured flower, does not appear 

 capable of playing havoc with its neighbours certainly not with 

 such forms as fishes and crustaceans (fig. 411). Appearances, 



however, are unusually deceptive in 

 this case, for the innocent-looking 

 "petals" are aggressive tentacles, 

 armed with innumerable ''nettling 

 organs", and they surround a large 

 mouth which can be easily stretched 

 so as to admit prey of compara- 

 tively large size. The modus oper- 

 andi is graphically described by 

 Fred Smith (in The Boyhood of a 

 Naturalist). The boy has brought 

 home from the sea -side his first 

 collection of marine animals, in- 

 cluding a large contracted ane- 

 mone, of which its donor, a friendly 

 fisherman, had said: "If he blows, 

 he'll astonish you; and if he ain't hurt he will, purviding you 

 put him into some of your fresh sea -water when you get 



Fig. 411. A Sea-Anemone. Notice mouth 

 surrounded by tentacles. 



