2G4 THE OCEAN WOKLD. 



and again retracts itself by means of its muscular fibres, by which 

 action the fluid is forced back into the interior. In progression the 

 animal extends a few of its feet, attaches its suckers to the rocks or 

 stones, then, by shortening its feet, it draws its body forward. The 

 progression of the Asterias is thus very slow, and so regular that only 

 the closest observation enables the spectator to discover the movement 

 which produces it. Like the movements of the hands of a watch, the 

 eye cannot quite follow it. When an obstacle presents itself if, for 

 example, a stone comes in its way it raises one of the rays in order 

 to obtain a point of support, then a second ray, and, if necessary, a 

 third, and thus the animal creeps over the stone with as much ease 

 as if it walked over the smooth sands. In the same way the animal 

 creeps up perpendicular rocks, which is accomplished by means of these 

 ambulacra and suckers. Fredol says : " If an Asteria is turned upon 

 its back it will at first remain immovable, with its feet shut up. 

 Soon, however, out come the feet, like so many little feelers ; it moves 

 them backward and forward, as if feeling for the ground ; it soon 

 inclines them towards the bottom of the vase, and fixes them one after 

 the other. "When it has a sufficient number attached the animal turns 

 itself round. It is not impossible, whilst walking on the sea-shore, 

 to have the pleasure of seeing one of these star-fishes walking upon 

 the sand. A day rarely passes without one of them being thrown upon 

 the strand by the tide, and then abandoned by the retreating waters. 

 Generally they are left dead; this is not always the case, however; 

 they are sometimes only benumbed. Place them in a vase full of sea- 

 water, or simply in a pool on the shore, and you will sometimes see 

 them recover from this death-like condition, and execute the curious 

 movements of progression which we have described. The motions of 

 an Asterias thus saved form a very curious spectacle. 



The mouth of this animal is situated on the lower surface of the 

 disk. At this point the constitutive pieces of the carapace leave a 

 circular space, covered by a fibrous resistant membrane, pierced at the 

 centre by a rounded opening. This opening is sometimes armed with 

 hard papillae, which play the part of teeth. The mouth almost 

 directly abuts on the stomach, which is merely a globular sac, filling 

 nearly all the central portion of the visceral cavity. 



" Thus," says Mr. Milne Edwards, " in Asteracantliion glacialis 

 the stomach is globulous, but imperfectly divided into two parts by a 



