68 GLIMPSES OF NATURE. 



Yet oysters have to open their shells in time in 

 order to breathe by inhaling the water; so that it 

 may be, our starfish, clasping its oyster, bides its 

 time, and when the shell is opened attacks the 

 mollusc. There are difficulties, however, in the way 

 of accepting the fishermen's belief, for the eviction of 

 an oyster from its shell by a starfish would, on the 

 best showing, be a very long and laborious matter. 

 One belief of naturalists is that the starfish poisons 

 the oyster by inserting from its stomach, between the 

 valves of the shell, some poisonous secretion, which 

 compels the mollusc to capitulate and surrender. 

 Anyhow, the belief is a curious one, and one may 

 not be surprised if on this occasion the fishermen's 

 ideas are regarded with greater favour than science 

 usually accords to the folk-lore of the dwellers by 

 the sea. 



Drop the starfish into this pool and watch its 

 movements. You have seen the hundreds of little 

 tube-feet, each ending in a sucker, which the grooves 

 on the under side of the rays contain. You observe 

 that it soon begins to crawl over the patch of rock on 

 which it has been dropped. Turn it over on its back 

 in the water, and observe how the feet move and 

 wriggle. Let us watch how the capsized animal 

 rights itself. Slowly but deliberately you see it 

 twists over the tip of two of its rays, until the tube- 

 feet have become attached to the rock. 



This is to give it a fulcrum or point d'appui, from 

 which to lever itself back to a respectable position. 

 The tips of these rays are firmly fixed to the rock, 

 and in turn the under parts of the two rays are 

 brought by the successive attachment of their feet in 

 contact with the rock-surface. Acting as levers, the 



