Amoeboid Movement 



631 



Amoebae differ greatly in cell form; Amoeba Umax has a single lobose 

 pseudopod (Fig. 239, D); the stellate form of amoeba has many free pseudo- 

 pods; A. proteiis and A. dubia (Fig. 239, A and C) are multipodal, i.e., they 

 have several attached pseudopods with streaming in various amounts in 

 each. Amoebae may have surface ridges, as in A. verrucosa (Fig. 239, E), 

 or they may have an irregular "tail" or uroid, as in Pelomyxa palustris (Fig. 

 239, F). Lymphocytes vary likewise, sometimes having a broad advancing 

 pseudopod and smaller tail, the "looking glass" shape, or they may be worm- 



v^,%. v.; 1;. v '' 



■'r'1%, f>r-;'-:' 



• 







B 



Nucleus 

 Food vacuole 



Contractile vacuole 



Plasmolemma 



Nucleus 



Contractile 



vacuole 



Plasmosol 



Food vacuole 





Pseudopod 



Hyoline layer 

 Uroid 



Fig. 239. Drawings showing various types of pseudopods. Typical multipodal amoeboid 

 cells: A, Amoeba proteus in locomotion; B, Amoeba discoides in locomotion; C, Amoeba 

 dubia in locomotion. From Schaeffer."' Typical monopodal amoeboid cells: D, Amoeba 

 Umax; E, Amoeba verrucosa. Note ridges on pellicle. From Kuhn.^' F, Pelomyxa palustris, 

 showing direction of flow of granules. Note iwsterior uroid. From Mast.'" G, A typical 

 heliozoan, Actinosphaerium eichhorni, showing axopods. From Kuhn.*^ 



