STAR-FISHES. 49 



presents ; slowly he perceives its rays to expand to its full 

 stretch, hundreds of feet are gradually protruded through the 

 ambulacral* apertures, and each apparently possessed of 

 independent action, fixes itself to the sides of the vessel as the 

 animal begins to march. The numerous suckers are soon all 

 employed, fixing and detaching themselves alternately, some 

 remaining firmly adherent, while others change their position ; 

 and thus, by an equable, gliding movement, the Star-fish 

 climbs the sides of the glass in which it is confined, or the 

 perpendicular surface of the sub-marine rock." 



It has been remarked, that the Star-fishes are furnished 

 with five rays ; and although individuals are met with which 

 have four or six rays, the five-rayed predominate so much, 

 that, among the problems proposed by Sir Thomas Browne, 

 is one, " Why, among Sea-stars, Nature chiefly delighteth in 

 five points?" Throughout all the animals of this class, five 

 is the governing number, regulating even the plates of which 

 the u shell " of the Sea-urchin is composed. In the Medusa, 

 the governing number is four ; and each Jelly-fish, with but 

 few exceptions, exhibits, in the arrangement of its parts, the 

 number four, or some multiple of that number. f 



Although the rays of the Crossfish, or "Five-fingers," arc 

 not mere arms, but true prolongations of the body, and, in 

 many species, have an eye well defended by spines at the 

 extremity, they are frequently broken off, and in such cases 

 are reproduced. The oyster fishermen believe that it loses its 

 rays in attempting to seize the oyster at a time when the shell 

 is incautiously left open. That it is iujurious to oyster-beds 

 may be true, for it is known to feed upon different kinds of 

 Mollusca; but it would appear to overpower its prey, by 

 applying some poisonous secretion, and pouting out the lobes 

 of the stomach, so as to convert them into a land of proboscis, 

 and thus suck the Molluscs from their shells. 



A species which Mr. Ball has taken in great abundance 

 about Youghal seems to emulate the Brittle-stars in the faci- 

 lity with which it can fling off its rays. It is appropriately 

 named Luidia fragilissima, and has been so graphically 

 delineated by Professor Ed. Forbes, that it would be doing 



* A term derived from the Latin word ambulacra, from a fancied 

 resemblance -which the rows of apertures bear to the walks, alleys, or 

 avtnucs of some of our old mansions. 



f Forbes, Intr. page 15. 



