238 THE AQUARIAN NATURALIST. 



within it when the animal is at rest ; but when in 

 action, it is protruded, unfolding a luxuriant flower, or 

 arboreseence, composed of a circlet of branching ten- 

 tacula. The body of many specimens, when in its 

 most natural position, assumes the form of a horse- 

 shoe or crescent, and a stream of water, playing like 

 a fountain, is at intervals forcibly discharged from its 

 posterior extremity. 



Few animals are apparently more helpless than a 

 Holothuria when found cast up upon the beach, as 

 was the case with the specimen in our vivarium ; and 

 yet, with the exception of the Echini, few have been 

 more liberally provided with locomotive organs. On 

 placing one of them in a tank of sea- water, down it 

 sinks to the bottom, and there it lies, to all appear- 

 ance as limbless and incapable of progression as a 

 Bologna sausage, and in this condition it will probably 

 remain for hours, without the slightest promise of 

 activity. At length, to the amazement of the be- 

 holder, it begins to stir ; nay, it begins to creep along 

 until it reaches the transparent side of the tank, and 

 then, amazement on amazement ! it soon proceeds 

 to climb, like a great slug, up its perpendicular sur- 

 face, gliding onwards with a slow and measured 

 movement in a manner that seems at first perfectly 

 incomprehensible. Close inspection, however, espe- 

 cially if aided by a magnifying-glass, reveals the 

 astonishing machinery employed for this purpose. 

 The whole surface of the body of the animal is found 

 to be covered with innumerable locomotive suckers, 

 which, both in their structure and mode of action, 

 exactly resemble those of the Echinus described in 



