THE LIVING CELL 25 
Move the slide if necessary so as to bring the organism into 
the center of the field of view. Swing on the clips and bring the 
high-power objective into position. Focus. 
Note that Amceba is a one-celled organism devoid of a cell 
wall, hence a naked mass of protoplasm. Protoplasm is a semifluid, 
viscid, granular like substance, in which life resides. It is 
shown by chemical analysis to consist mainly of certain sub- 
stances known as proteids, bodies of extreme complexity in 
chemical constitution, examples of which are white of egg or the 
albumen of blood serum. Besides proteids, the protoplasm of 
Fic. 15.—The Amceba. A, An amoeba moving in the direction of the arrows; 
n, nucleus; v, contractile vacuole; f, food within food vacuole. B, the process of 
fission in Amoeba, a nucleus in each half. B, after Jordan, Kellogg and Heath. 
(From Bergen and Davis Principles of Botany.) 
Ameeba contains fats and small proportions of mineral matters 
such as salts of potassium, calcium, magnesium and iron. It 
also contains a large proportion of water, called water of 
organization. 
Protoplasm is caused to shink by strong alcohol, which with- 
draws the water of organization. It is coagulated by heat and 
dissolved by prolonged treatment with weak acids or alkalies. 
Note that the protoplasm of the Amceba consists of an outer 
non-granular portion called the ectoplasm and an inner portion 
called the endoplasm. Within the endoplasm is to be found the 
nucleus which in the Ameeba is difficult to discern without the 
use of special stains. 
