UNICELLAR ANIMALS. 13 
inorganic and unorganized food, also organized matter in the 
form of a complex organic compound known as protein, which 
Fies. 8 to 15, represent successive phases in the life-history of an Amceboid organism, kept 
under constant observation for three days ; Fig. 16 a similar one encysted, which 
was afew hours later set free by the disintegration of the cyst. (All the figures are 
drawn under Zeiss, D. 3.) 
Fig. 8.—The locomotor phase ; the ectoplasm is seen protruding to form a pseudopodium, into 
which the endoplasm passes. . : 
Fig. are stage in the ingestive phase. A vegetable organism, fp, is undergoing intussus- 
ception. 
Fie. 1 Tie portion of the creature represented in Fig. 9 after complete ingestion of the food- 
particle. 
Fies. 11, 12.—Successive stages in the assimilative and excretory processes. Fig. 12 repre- 
sents the organism some twenty hours later than as seen in Fig. 11. The undigested rem- 
nants of the ingested organism are represented undergoing ejection (excretion) at fp, in 
Figs. B, 14, 15, represent successive stages in the reproductive process of the same individ- 
ual, observed two days later. It will be noticed (Fig. 13) that the nucleus divides first. 
In the above es, ve, denotes the contracting vacuole ; nc, the nucleus; ps, pseudopo- 
dium ; dt, diatom ; fp, food-particle. 
contains nitrogen in addition to carbon, hydrogen, and oxygen. 
In fact,,Amoeba can prey upon both plants and animals, and 
thus use up as food protoplasm itself. The pseudopodia serve 
the double purpose of organs of locomotion and prehension. 
This creature absorbs oxygen and evolves carbon dioxide. 
