THE PEOTOZOA 



B. Structure. 



The whole body is a naked mass of protoplasm, which is 

 of two kinds. 



1. The ectosarc is the clearer outer portion of the body. 



2. The endosarc is the granular and usually more fluid 



central portion. Its flowing movements, which 

 accompany the protrusion and retraction of the 

 pseudopodia, are rendered obvious by the granules 

 contained in it. 



.-..-A 



Fias. 1 to 8. — Amoeba ; 



(C. H. H.) ' 



Pigs. 2 and 3 were drawn from the same specimen, wMeh was moving 

 in the direction shown by the arrow. Pig. 4 is a form with branch- 

 ing pseudopodia. Pigs. 6 to 8 were drawn from one specimen at 

 intervals oi about twenty seconds. 



U, nucleus. P, pseudopodium. P V, pulsating vacuole. 



Within the endosarc make out the following structures. 

 a. Vacuoles are spaces filled with fluid, which is less 

 dense than the surrounding protoplasm. They 

 contain in many eases foreign particles taken in 

 as food. 



