128 THE STAE-FISH'S METHOD OP ATTACK. 



" The oystermen believe that it loses its rays in consequence of its 

 oyster-hunting propensities. That it insinuates an arm into the incautious 

 oyster's gape, with the intent of whipping out its prey, but that some- 

 times the apathetic mollnsk proves more than a match for its radiate ene- 

 my, and closing on him holds him fast by the proffered finger; then the 

 cross-fish, preferring amputation and freedom to captivity and dying of 

 an oyster, like some defeated warrior, finding 



' The struggle vain, he flings his arms away, 

 And safety seeks in flight.' 



" This story has long been believed. Link gives a vignette represent- 

 ing the mode of attack, with the motto ' sic struit insidias.' " 



Everybody who knows anything about it understands now, of course, 

 that all this is absurd. The star-fish goes about his foraging in a much 

 more effective and sensible way. Indeed, he excels almost any other ani- 

 mal worth calling one in economy of exertion in eating, since to secure, 

 swallow, and digest his food, when once he has forced an entrance to the 

 victim's shell, is combined in a single operation. 



Having met with an oyster, scallop, or other thin-shelled mollusk — '■ 

 and young ones are preferred because their armor is weak — the star-fish 

 folds his five arms about it in a firm and deadly grasp. Then protruding 

 the muscular ring at the entrance of his stomach through the circular 

 opening in the centre of the under side of the disk, which I have de- 

 scribed, he seizes the thin, newly grown, posterior edge of the shell, which 

 oystermen call the " nib " or " bill," and little by little breaks it off. It 

 has been surmised that the gastric juice decomposed the edge of the shell 

 until an opening was effected ; or, entering, paralyzed the mollusk, until 

 he relaxed the muscle which held the protecting valves together. But I 

 do not think either of these suppositions supported by fact. The opera- 

 tion is proceeded with too rapidly to wait for the slow action of the stom- 

 ach-acids upon the carbonate of lime in the shell ; and the vital parts of 

 the mollusk are too far inward and sluggish to be promptly affected by 

 any such acids. Moreover, it seems unnecessary, since the appearance of 

 every shell attacked at once suggests a breaking down, chipping-off move- 

 ment, which the star-fish might easily produce by seizing and suddenly 

 pulling down with the suckers nearest the mouth, or by a contraction of 

 the elastic opening of the stomach. 



However managed, the thin edge of the shell is broken, until an en- 

 trance is made which the occupant has no way of barricading. Then the 

 burglar protrudes into this entrance the distensible mouth of his stomach 



