14 FIRST LES80N8 IN ZOOLOGY. 



is enveloped within the body, which is so transparent that 

 the food-object can be seen through it. The Amcsba has 

 the power of digesting and of distributing and absorbing 

 the food (Fig. t, h, food-ball) when digested. 



The Amoeba reproduces its kind by simply dividing into 

 two portions, as seen in Fig. 8. After becoming encysted 

 or forming a round mass as at B, it breaks out of the cell- 

 wall and becomes free and irregular in shape as at ^. 

 Self-division then begins as at C, the nucleus dividing into 

 two, until at Da and Db two separate individuals are formed. 



When the Amoeba is touched it (1) contracts its body— 



Fig. %.—Amci^a. A, before diyision. B, the same in its resting stage; a, cyst 

 or cell-wall; d, body-mass; c, nucleus; 6, nucleolus. C, Amoeba, nearly divided. 

 D, two young Amoebse, the result of division. (Highly magnified.) 



it is thus said to be contractile — and (2) performs auto- 

 matic movements; also, like the higher animals (3), it 

 swallows food; (4) chemical changes in the food take place: 

 in other words, it digests its food, i.e, separates or secretes 

 the portion necessary to nourish its body from those por- 

 tions which it excretes or rejects as waste; (5) it may also 

 be said to breathe, the changes involved in taking food 



