32 ELEMENTARY ZOOLOGY 



from certain parts of the body ? Within the endosarc 

 note a clear globular spot which contracts and expands, 

 or pulsates, more or less regularly. This is the contrac- 

 tile vacuole. Note the small granules which move about 

 within the endosarc. These are food-particles which 



FIG. 5. Amceba sp. ; showing the forms assumed by a single individual in 

 four successive changes. (From life.) 



have been taken in through the body-wall. Note how 

 pseudopodia flow about food-particles in the water and 

 how these are digested by the protoplasm. If an Amoeba 

 comes into contact with a particle of sand, note how it at 

 once retreats. Note within the endosarc an oval trans- 

 parent body which shows no pulsations. This is the 



