GENERAL CHARACTERS OF STAR-FISH. 4f>7 



is continued into them. Some are so little divided at the 

 edges, that in external form they approach the Clypeasters 

 ( 1102); whilst in others the disk seems almost absent, the 

 animal being, as it were, all rays. In general organization, 

 however, there is a pretty close correspondence throughout. 

 The Asterice appear to enjoy a considerable amount of loco- 

 motive power. Their rays are very flexible, so that they 

 can be drawn up towards the mouth, or moved from side to side 

 towards each other, so as to give the animal the power of insi- 

 nuating itself through narrow apertures. The rays appear to be 

 principally moved by the general integument, which is thick 

 and contractile. Small red points have been observed at their 

 extremities in some species, which, from their connection with 

 the nervous cord of each ray, and from their analogy with the 

 eyes of other Invertebrata, are believed to be visual organs. 

 This belief is strengthened by the observation of Professor 

 Forbes, that the spines are disposed around them in a peculiar 

 circular mode, so that they may be closed over these organs 

 for their protection, or may diverge for their most extended 

 employment. The same gentleman has remarked that these 

 animals appear to take cognizance of objects of food placed at a 

 little distance from them ; and that, in their movements from 

 place to place, they seem to be aware of obstacles in their direct 

 path, and to go out of their way to avoid them. It has been 

 remarked also that, when all their feet are protruded, they will 

 suddenly retract them, if any substance be brought in close 

 proximity to them, but without touching them. 



1106. Notwithstanding their possession of this amount of 

 perceptive power, however, they do not seem to be very sus- 

 ceptible to painful impressions. If severe mutilations be per- 

 formed whilst the animal is in a state of activity, it does not 

 appear conscious of them, but continues its movements as before. 

 The suckers in the neighbourhood of the injured part are re- 

 tracted ; but the others, even in the same ray, continue their 

 actions, as if unaffected by the sense of injury. Of the extent to 

 which reproduction of parts may take place after such mutila- 

 tions, details have already been given. The Asterice are animals 



