62 PRACTICAL ZOOLOGY. 



AMCEBA. 



One of the simplest forms of animal life is Amoeba. It 

 is found in standing water, where it lives on the leaves of 

 submerged plants or in the mud and ooze at the bottom. 



Scrape up a thin layer of the ooze and allow it to stand 

 a few days. 



Place a drop of such water, with a little of the sedi- 

 ment, on a clean slide, and cover with a clean cover-slip ; 

 if there be no solid matter in the drop of water, lay a 

 strip of paper on the slide before putting on the cover- 

 slip, letting one edge of the cover rest on it. Examine 

 with a high-power objective. 



The amoeba is like a minute drop of jelly, pale (nearly 

 colorless), with a more dotted central portion. Its most 

 noticeable characteristic is its slow, peculiar mode of 

 changing its form. 



The following parts of the body should be made out : 



1. A clearer outer margin. 



2. A dotted or granular inner portion. 



3. A clearer, round body, in the granular part, called the 

 nucleus. 



Study carefully the movements of the amoeba ; first a 

 part of the clear outer portion bulges out, or is sometimes 

 thrown out as a long projection, called a pseudopodium ; 

 then the granular part flows into this, and by repeating 

 this process the amoeba creeps along with a slow gliding 

 motion, though sometimes the pseudopodia are thrust out 

 and retracted without moving the body as a whole ; care- 

 fully watch the beginning and the whole process of form- 

 ing a pseudopodium ; look for movements of the granules 

 in the central portion. 



