MAEOE BOTANY. 107 



polishing slate, which occupies several square miles — for 

 they have merely a local distribution — while the Foraminif era 

 inhabit all waters. 



The similarity of their shells to those of the Xautili and 

 Ammonites, led at first to the belief that these gracefully 

 spiralled calcareous shells were formed by similar animals, 

 and their smallness was ascribed to the exhaustion of a 

 form, which no longer found the conditions of its earlier 

 growth, in the altered state of the temperature and the 

 components of the sea. Closer examination has, however, 

 proved that they are animals of a very low order, which 

 stand in close relation to the Amseba, also found in every 

 sea. Other animals amaze us by their composite structure, 

 the multiplicity of their organs, while each, designed for a 

 special purpose, forms a harmonious whole; but, in the 

 Amaeba, the extremely simple structure of the body arouses 

 our highest admiration. Nowhere do the mysteries of vital 

 strength appear to us in a more wondrous light than in this 

 case, where it reveals its most secret arrangements without 

 any appointed instruments. The Amseba is nothing but an 

 animated being, of a loose, pellucid, colourless, contractile 

 substance, whose individual life is revealed by various 

 changes of form, which bear the character of arbitrary 

 motion. The larger mass of the body floats after a rounded 

 or pointed, longer or shorter, continuation, which can grow 

 from any part of the body : similar continuations grow 

 afresh, and produce, by the constant change of motion, 

 protsean alterations of form in this simplest of all animal 

 bodies. There is no distinction between cuticle and body in 

 them; and the movements of these beings appear acts of 

 volition; but there are no special organs of motion and 

 feeling in their simple forms. They cannot exist in a body 

 whose parts are so thoroughly equivalent, that each grain 

 can at any moment change place with another. 



The substance seems not only regularly contractile, but 

 also equally irritable at every part of the body, and adapted 



' 



