266 
THE OCEAN WORLD. . 
and again retracts itself by means of its muscular fibres, by which 
action the fluid is forced back into tbc interior. In progression th e 
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. Th 6 
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, f° r 
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, 9 
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. FrJdol says : “ If an Asteria is turned up 011 
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 move® 
them backward and forward, as if feeling for tbe ground ; it sooU 
inclines them towards the bottom of the vase, and fixes them one after 
the other. When it has a sufficient number attached the animal turn® 
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 up 011 
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 se e 
them recover from this death-like condition, and execute the curiou® 
movements of progression which we have described. The motions el 
an Asterias thus saved form a very curious spectacle. 
The mouth of this animal is situated on the lower surface of th® 
disk. At this point the constitutive pieces of the carapace leave 9 
circular space, covered by a fibrous resistant membrane, pierced at th e 
centre by a rounded opening. This opening is sometimes armed with 
hard papillae, which play the part of teeth. The mouth alm° s * 
directly abuts on the stomach, which is merely a globular sac, fiH lB » 
nearly all the central portion of the visceral cavity. 
“Thus,” says Mr. Milne Edwards, “in Asteracayithion 
the stomach is globulous, but imperfectly divided into two parts by 9 
