ACTINIA OR SEA-ANEMONE. 497 



1063. The muscular structure of the fleshy base of the inner 

 part of the general envelope of the radiating partitions, and of 

 the circle round the mouth, is very distinct in the larger species 

 of Actinia, and confers upon the animal considerable power in the 

 prehension of food. Dr. Grant mentions that he has caused the 

 common Actinia crassicornis to lift a basin of sea-water, weighing 

 more than six pounds, by making it swallow the perforated shell 

 of a Purpura, through the aperture of which a cord had been 

 passed. By this cord the basin was lifted, without the Actinia 

 quitting its hold either of the shell in its contracted stomach, or 

 of the basin to which its foot was attached. It is not surprising, 

 therefore, that these polypes should be able to master not only 

 shell-fish and other animals that have little means of active 

 resistance, but even crabs, prawns, and other Crustacea of con- 

 siderable size. These, indeed, seem to constitute its ordinary 

 food. The luckless individual which walks over one of these 

 stomachs gaping for its prey, is immediately secured by its ten- 

 tacula, and in spite of its struggles is drawn into the mouth, 

 which seems capable of distention to an almost unlimited degree. 

 Sometimes the tail of a shrimp, or some other hard projecting 

 appendage, will occasion a little trouble, and may be seen in 

 active movement outside the mouth, when the mass of the body 

 has been swallowed ; but this is soon restrained by the tenta- 

 cula, which entwine themselves round it, and gradually convey 

 it into the stomach. These tentacula possess a remarkably 

 tenacious power, which has been attributed to a glutinous 

 exudation from them ; but nothing of this kind can be seen on 

 surfaces to which they have firmly attached themselves, and 

 their adhesion is more probably due to the temporary conversion 

 of a part of the arm into a sort of sucker. 



1064. The digestive powers appear very considerable ; for 

 when Mollusca or Crustacea have been swallowed, the shells are 

 subsequently rejected by the mouth, with not only their soft 

 contents, but even their tendinous and ligamentous portions, dis- 

 solved away. It has been said that the Actinia sometimes 

 swallows a shell, of which it cannot get rid in the usual manner, 

 owing to its broad diameter being turned to the mouth ; and 



