564 ASTERIAS, OR STAR-PISH. 



guarded by a shelly defence ; they swallow various kinds of uni- 

 valve shell-fish, the smaller kind of crabs, and other animals ; and 

 when they have absorbed the juices of their prey, they reject the 

 shell or other integument by the mouth. When kept in vessels of 

 sea-water, which may be easily practised, they seem to require no 

 particular nutriment, absorbing a sufficient quantity of animal 

 gluten, from the sea-water itself, for all the purposes of nutrition. 

 In this confined state they do not grow or increase in size, though 

 they frequently produce a numerous offspring, being of a very pro- 

 lific nature, and viviparous. The young are produced of various 

 sizes, from that of a pin's head to that of half an inch in diameter, 

 and to the number of five, ten, or more at a birth. As these ani- 

 mals are allied to the polype tribe in some degree, they partake of 

 their qualities, and will reproduce many of their organs, when 

 either purposely or accidentally mutilated. 



3. Asterias, or Star-Fish. 



Most of these are of a stellated or radiated shape, as their name 

 imports ; the rays differing in number in different species, from five 

 to ten or twelve. The most curious of the whole tribe, is A. Caput 

 Medusae, of Linnaeus, or Medusa's head star-fish. It grows to a 

 large extent, measuring more than two feet in diameter when the 

 limbs are fully extended. This very extraordinary animal is first 

 divided into five equidistant, jointed processes, each of which is soon 

 subdivided into two other smaller ones ; and each of these, at a 

 somewhat farther distance, into two others, still smaller ; this mode 

 of regular subdivision, being continued to a vast extent, and in the 

 most beautiful gradation of minuteness, till at length the number 

 of extreme ramifications amounts to several thousands. By this 

 most curious structure, the animal becomes, as it were, a kind of 

 living net j and is capable of catching such creatures as are destined 

 for its prey, by the sudden contraction of all its innumerable rami- 

 fications, and thus the object is secured beyond all power of escape. 

 Examples of this animal, well worthy of notice, are to be found in 

 the British, and were formerly in the Leverian Museum. 



The sea-stars, in general, have a very considerable degree of re- 

 productive power; and if injured by accidental violence, or if one 

 or more of the limbs be cut or torn off, the animal will in time be 

 furnished with new ones. They wander about the ocean in quest of 



