POLYPES. 



71 



by presenting to the Sea- Anemone any small shellfish or 

 an atom of raw meat. When a tentacle comes into con- 

 tact with it, it contracts forcibly, and the prey is thus 

 dragged upon the oral disk, the surrounding tentacles 

 arching over it. The lips instantly begin to protrude, 

 stretching out towards the morsel, which they presently 

 embrace, and gradually enclose, extending their volume, 

 until they close over it, sucking it in as it were, and forcing 

 it to disappear within the body. Digestion now takes 

 place ; and in the course of the next twenty-four hours 

 the remains, such as the shell of the mollusk, or the hard 

 parts of a little crab, are disgorged through the mouth, 

 enveloped in a tenacious, slimy mucus. 



Though commonly the prey of the Actiniae is small, it 

 is not always so ; the voracious creature occasionally 

 mastering and swallowing a victim even much larger than 

 itself, strange as such a proposition may sound. Dr 

 Johnston has recorded from his own experience an example 

 of this. " I had once brought me," he observes, " a 

 specimen of Actinia crassicornis, that might have been 

 originally two inches in diameter, and that had somehow 

 contrived to swallow a valve of the great scallop (Pecten 

 mdocimus), of the size of an ordinary saucer. The shell, 

 fixed within the stomach, was so placed as to divide it 

 completely into two halves, so that the body, stretched 

 tensely over, had become thin and flattened like a pancake. 

 All communication between the inferior portion of the 

 stomach and the mouth was of course prevented, yet, in- 

 stead of emaciating and dying of an atrophy, the animal 

 had availed itself of what undoubtedly had been a very 

 untoward accident, to increase its enjoyments and its 



