CHAPTER VI 

 AMCEBA AND PARAMCECIUM 



LABORATORY EXERCISE 



Amoeba. TECHNICAL NOTE. Amoeba are found in stagnant 

 pools of water on the dead leaves, sticks and slime at the bottom. 

 To obtain them, collect slime and water from various puddles in sepa- 

 rate bottles and take them to the laboratory. Place a small drop of 

 slime on a slide under a cover-glass. Examine under the low power 

 first and note any small transparent or opalescent objects in the 

 field. Examine these objects with the higher power and note that 

 some are mere granular jelly-like specks, which slowly (but con- 

 stantly) change their form. These are Amoeba. 



A teacher of zoology recommends the following method of obtain- 

 ing a large supply of A mceba : "For rearing Ama'ba place two or 

 three inches of sand in a common tub, which is then filled with 

 water and placed some feet from a north window ; three or four 

 opened mussels, with merest trace of the mud from the stream in 

 which they are taken, are partially buried in the sand and a hand- 

 ful of Xitclla and a couple of crayfish cut in two are added ; as 

 decomposition goes on a very gentle stream is allowed to flow into 

 the tub, and after from two to four weeks abundant Amoeba are to 

 be found on the surface of the sand and in the scum on the sides of 

 the tub ; small Amoeba appear at first, and later the large ones." 



Having found an Amaba (fig. 5) note its irregular 

 shape, and if it moves actively observe its method of mov- 

 ing. How is this accomplished ? The viscous, jelly-like 

 substance which composes the whole body of an Amceba 

 is called protoplasm. The little processes which stick 

 out in various directions are the "false feet" (pseudo- 

 podia). Note that the outer portion, the cctosarc, of the 

 protoplasmic body is clear, while the inner, the endosarc, 

 is more or less granular in structure. Has Amoeba a 

 definite body- wall ? Do the pseudopodia protrude only 



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