8o 



THE PROTOZOA 



The nature and the number of pseudopodia have frequently been 

 used as a method of identification of certain species of Rhizopoda. 

 Amceba polypodia, A. radiosa, and A. proteus have certain characteris- 

 tic pseudopodial structures which are seemingly of diagnostic value, 

 yet A. proteus under the influence of a constant electric current can 

 be made to assume the forms characteristic of A. polypodia and then 



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Fig. 44. Types of pseudopodia. 



A. Amoeba limicola'Khmh. [RHUMBLER.] B. Amoeba blatta: Butsch. [BUTSCHLI.] C. Lie- 

 berkiihnia sp. [VERWORN.] D. Actinospharium Eich. Ehr. [ORIGINAL.] x, axial filament. 



of A. Umax. Conversely, A. Umax, when placed in an alkaline solu- 

 tion of potassium hydrate, becomes transformed into A. proteus, and 

 later, into A. radiosa (Verworn, '94). When a change in the surround- 

 ing medium can so affect the protoplasm that the entire character of 

 pseudopodia-formation is altered, the specific value of pseudopodia 

 alone may well be questioned, and species based upon such a variable 



