PHYSIOLOGICAL ACTIVITIES OF THE PROTOZOA 75 



while its struggles furnish the stimulus for an accumulation of more 

 protoplasm about it, and this, armed with digestive fluids, soon kills 



FIG. 23 



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\ 



-..^j.,. , >, ; --o. -x : '. j- \r-*3f \ f l-e- .(&> 



>^T*s Y\ ^\'- \1 J^^mr^ 



Allogromia, sp., with pseudopodial net and two diatoms. (After Calkins.) 



