296 
ZOOLOGY: M. BUNTING 
Proc. N. a. S. 
life cycle, a period of about four days. A brief description of the living 
animal during the stages of its life cycle will now be given. 
1. The Cyst:— {fig. 1, A) a. Morphology. Commonly spherical, 
occasionally broadly oval, single, smooth, relatively thin wall; usually 
uninucleate; rarely binucleate; size ranging from 6m to 18 /i. 
FIGURE 1 
Diagram of life-cycle of coprozoic amoeba with Tetramitus as its flagellate phase. 
A — the cyst; B — vegetative amoeba; C, C — division ("gel" state); D, D' — amoebae 
after division; E, F — phases in transformation of Tetramitus; G — fully formed Te- 
tramitus; H — Tetramitus previous to division ("gel" state); I, I' — Tetramitus after 
division; J, K, Land J', K', L' — series of transformation stages, Tetramitus to amoeba. 
h. Excy station. No empty cyst wall remains after the amoeba has 
emerged from the cyst, the wall apparently undergoing solution during the 
process of excy station. 
