THE KHIZOPODA. 



11 



tureless and without permanent distinction or separation of parts 

 is, to my mind, a fact of the profoundest significance. 



Though a Rhizopod is not permanently organized, however, 

 it can hardly be said to be devoid of organs ; for the name of 

 the group is derived from the power which these animals possess 

 of throwing out processes of their substance, which are called 

 " pseudopoclia," and are sometimes very slender and of great 

 length (Fig. 2, E), sometimes broad and lobe-like (Fig. 2, A). 



Fig. 2. 



Fig. 2. A, B, Free and encysted conditions of an Amoeba (after Auerbach) ; E, a Fora- 

 minifer (Rotalia) with extended pseudopodia ; D, its shell in section (after Schulze). 



These processes may flow into one another, so as to form a net- 

 work, and they may, commonly, be thrust out from any part of 

 the body and retracted into it again. 



If you watch one of these animals alive, you see it thrusting 

 out, first one and then another of its pseudopodia, exhibiting 

 changes of form comparable to those which the colourless 

 corpuscles of the human blood present. The movements of 

 these Ehizopods are quite of the same character ; they are 

 rapid, extensive, and effect locomotion. The creature also feeds 



