AMCEBA. 



Phylum I, PROTOZOA; class i, RHIZOPODA; order i, LOBOSA. 



HABITAT. The Amoeba is a minute, jelly-like speck of protoplasm 

 found on submerged weeds and leaves in pools and ditches, or in the 

 slime at the bottom. Amoebae also occur- in damp places not under 

 water. 



Technical Note. Wilh a pipette or the point of a scalpel, place on a 

 slide a little of the water and slime" from the surface of objects sub- 

 merged in an aquarium jar containing AmcebcB. Cover, and study 

 with a moderately high power of the microscope. 



APPEARANCE. The Amoeba will appear as a small, semi-trans- 

 parent object of irregular outline. As the individuals vary much in 

 size, some will not be seen without a high power of the microscope, 

 while others may almost fill up the field. The larger specimens will 

 be best for study. 



DETAILS. You should be able to make out a clear outer layer of 

 the protoplasmic body ectosarc and an inner, more granular mass, 

 the endosarc. There is, however, no true cell wall. The granules 

 of the endosarc are merely the products of certain life processes. 

 Watch for movements of the animal simple outpushings of the ectosarc 

 into which granules of the endosarc slowly stream. These blunt pro- 

 jections from the central mass of the Amoeba are called pseudopods 

 or false feet. Within the endosarc note the contractile vacuole, 

 a clear globule that slowly increases in size and then suddenly disap- 

 pears only to reappear shortly and repeat the action. This performance 

 is supposed to represent the excretion of waste matter which is gradually 

 accumulated and then suddenly squeezed out into the surrounding 

 water by the globule's collapsing near the periphery of the body. 

 Try to time the so-called pulsations of these vacuoles. 



If opportunity offers, study the Amoeba's method of taking food 

 and of excreting the indigestible portions of the same. Around each 



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