730 ROBERT MCCARRISON. 
species of Schaudinn will be referred to in the course of my 
description. 
Amoeba I. 
The unencysted amceba usually appears as a spherical 
body of variable size, ranging up to 20m in diameter. The 
protoplasm is finely and evenly granular (text-fig. 8). I can 
detect no differentiation into ectoplasm and endoplasm. 
In some the protoplasm contains food-material and various 
inclusions, while in others it appears to be free from 
TEext-FIG. 15. 
Thxm-nie, 16: 
Text-fig. 15— Ameba I. Enecysted ameba. The nuclear 
division has resulted in the formation of five nuclei. 
Text-fig. 16—Ameba Il. Eneystedameba. Typical 8-nucle- 
ated cyst, of very common occurrence in feces. Hach nucleus 
is ring-like with a small karyosome in its interior. A few small 
chromatin masses are seen. 
extraneous matter. Such inclusions as blood-corpuscles or 
epithelium have never been met with. The protoplasm rarely 
shows a vacuole. The nucleus is very distinct, and is usually 
centrally placed (text-fig. 8). It is commonly surrounded by 
a narrow but distinct halo. In text-fig.8 the nucleus appears 
to lhe in a cavity lined by a membrane. Since it has been 
preserved in a sublimate mixture the appearance may be due 
to shrinkage of the protoplasm. The nucleus stains deeply ; 
it is rich in chromatin, which in the adult unencysted animal 
is more or less uniformly distributed throughout this structure. 
‘here is often a slight tendency for the chromatin to be 
