CHAPTER V 

 AMCEBA, PARAMCECIUM AND VORTICELLA 



Amceba. — Technical Note. — Amosbcs 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 separate 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 mnd note any 

 small transparent or opalescent objects in the field. Examine these ob- 

 jects with the higher power and note that some are mere granular 

 jelly-like specks, which slowly (but constantly) change their form. 

 These are AmmbcB. 



A teacher of zoology recommends the following method of obtaining 

 a large supply of Amxbm: "For rearing Amoebm 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 handful of Nitella 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 Ammbm are to be found on the surface of the sand and in 

 the scum on the sides of the tub; small Amoiba appear at first, and 

 later the large ones." 



Having found an Amceba (fig. 12) note its irregular shape, 

 and if it moves actively observe its method of moving. How 

 is this accomplished? The viscous, jelly-hke substance 

 which composes the whole body of an Amoeba is called 

 protoplasm. The little processes which stick out in various 

 directions are the "false feet" (pseudopodia). Note that the 

 outer portion, the ectosarc, of the protoplasmic body is clear, 

 while the inner, the endosarc, is more or less granular in 

 structure. Has Amaiba a definite body- wall? Do the 

 pseudopodia protrude only from certain parts of the body? 



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