THE ANIMAL A MACHINE 



159 



Fig. 60. Amoeba Proteus Floating in Water 



This is a one-celled animal consisting of a soft, almost liquid, material 

 which changes its form continuously. As indicated in the figure by arrows, 

 some of the protrusions of the animal, termed pseudopodia, retract while 

 others are extended. (Magnified 200 times.) 



Fig. 61. Amoeba Moving Forward in the Direction of Arrow 



The entire liquid body content of the amoeba streams forward as it 

 moves on. The pseudopodia in front are extended while those in the rear 

 are retracted. As the figure shows, the animal is thus enabled to overcome 

 small obstalces by throwing the pseudopodia across these obstacles. 



