RHIZOPODA. 35 
position. When, however, the anatomical structure of the 
group came to be investigated, it was soon found that they were 
really referable to the Pro¢ozoa, and that in point of fact they 
even occupy a low position in this sub-kingdom. However 
elaborate and complicated the shell may be, the body of the 
contained animal is composed simply of granular gelatinous 
Fig. 5.—Foraminifera. a'The animal of Noxioniva, after the shell has been removed 
by a weak acid ; 4 Gromia (after Schultze), showing the shell surrounded by a 
network of filaments derived from the body-substance. 
sarcode, highly elastic and contractile, and usually reddish or 
yellowish in colour (fig. 5, a). This sarcode not only fills the 
shell, but also in many cases gains the exterior by means of 
little perforations in its walls, and forms a thin film over its 
outer surface. Wherever the sarcode is exposed, whether this 
