HOW STAB-FISHES EAT OYSTERS. 205 



men assert that they have seen the enemy flagrante 

 delicto, they are by no means either close or accurate 

 observers. 



" I have not heard it suggested/' says Sir John, 

 " that the Star-fish possesses any kind of solvent 

 compelling the bivalves to sunder. Neither can its 

 hostility be very deadly to the larger univalves, from 

 the distance to which they are enabled to retreat 

 within their portable dwellings. Their general habits 

 are, to force the shells of smaller bivalves asunder, 

 and to devour the contents ; they likewise consume 

 the substance of ordinary fishes entire ; nevertheless, 

 as far as I am yet aware, their destruction of oysters 

 is destitute of evidence. The Star-fish sometimes 

 shows an eversion of the stomach, or of some mem- 

 brane resembling it. Whether this may be the means 

 of affecting their prey merits investigation." 



In this latter suggestion, Sir John Dalyell has very 

 nearly hit upon the true solution of the problem. 

 There are more ways than one even of eating an 

 oyster, and the method adopted by the Asterias is 

 peculiar. It is quite evident, from the small size and 

 undilatable structure of the mouth of the Star-fish, 

 that it can never introduce an oyster, shells and all, 

 into its stomach, more especially as the edible mol- 

 lusk is always firmly fixed upon its bed ; but that is 

 no reason why it should not put its stomach into the 

 oyster, and thus effect its purpose in a different 

 manner. Its mode of proceeding is as follows : 

 Grasping its shell-clad prey between its rays, and 

 firmly fixing it by means of its prehensile suckers, it 

 proceeds deliberately to turn its stomach inside out, 



