iS6 



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. 



