RKl'OUT OF COMMISSION KK.S OF JNLAM) JvlSlI Hlil ES. 17 



By means of these ambulacral feet tlie animal walks or crawls. 

 The progress is slow, it is true, but sure, for there is no slip- 

 ping, and in a few hours a surprisingly long distance can be 

 covered. The feet are so numerous, and the movement so even, 

 that the animal seems rather to glide than to crawl. Moreover 

 the sea-water buoys up the star-fish so that it does not have its 

 weight to support. The star-fish will move easil}^ up the smooth 

 surface of a vertical glass plate or along the underside of a horizon- 

 tal j)lane. I liave often seen small stars, measuring about three- 

 eighths of an inch from centre to tip of arm, crawl up the side of 

 the aquarium and then glide along the surface of the water. 

 During this performance the star is always on its back, and the 

 suckers extend to the surface of the water. 



The buoyancy of the water and the great number of feet enable 

 the animal to move over the lightest silt as well as over hard sur- 

 faces. Even large star-fish are able to pass through very narrow 

 and irregular crevices, for the skeleton is composed of innumer- 

 able small plates, joined together, and provided with muscles 

 which allows the body to adapt itself to the shape of the crevice. 

 The star-fish, unlike many other marine animals, snails, worms, 

 etc., will never creep out of the sea-water, nor even protrude an 

 arm above the surface. It will never cross a barrier that extends 

 even a little above the surface of the water. 



The star-fish is generally believed by fishermen to have a much 

 more active mode of locomotion than that of crawling. The tradi- 

 tion is tliat large numbers of stars cling together to form a com- 

 pact ball from a foot to three feet or more in diameter, which 

 is rolled along the bottom by the tide until, striking an oyster 

 bed, the ball goes to pieces and the stars begin work at once. 

 It is difficult to find an actual eye witness of this ]3henom- 

 enon, though Ernest IngersoU tells of an old oysterman, " Captain 

 Eaton, of New Haven, who said that he and his brother once raked 

 up the end of a cylindrical roll of star-fishes clinging tightly to- 

 gether, which they hauled into their boat until it would contain 

 no more, when they had to break the roll or ' string,' as he called 



