92 LIFE AND HER CHILDREN. 
feet, which it never uses for walking, although it 
fills them through a porous plate like the star-fish. 
Its soft body too is all contained within the round 
cup in the centre, and its arms do not open out of 
it as in the star-fish, but are joined on ; and this may 
partly explain why it so often flings its arms into a 
hundred pieces when frightened ; for it can afford to 
part with them, and can soon form them again. 
As tools and weapons, however, they are most 
useful, and the reason why the brittle-star does not 
use its tubes as feet is that its arms are quite 
sufficient to carry it along. Made of a number 
of small plates joined together by elastic muscles, 
and fringed with hooks and spines, these stony rays 
serve both as walking and feeding apparatus. The 
animal twists them to and fro in all manner of 
contortions, and in this way is carried over the rocks 
at a surprising pace, while it can bury itself in the 
sand and mud with the greatest ease, or wriggle into 
the smallest crevices if it fears to be attacked. 
If the star-fish is remarkable for its smooth gliding 
motion, the brittle-star is the prince of wrigglers, and 
must escape many dangers by its bewildering activity. 
Indeed, we may almost fancy that its enemies may 
be as startled at its wild contortions as the fishermen 
were who dredged the brittle-stars up for Professor Ed- 
ward Forbes, and begged to be allowed to throw them 
back, saying, " the things weren't altogether right ! " 
On the other hand, there is little doubt that they 
use their arms to carry food to the mouth, and one 
of this family called the " Basket-Fish," * has its rays 
so branched and curled that they interlace, forming 
* Shown in the left-hand corner of the Frontispiece. 
