RHIZOPODS. 
553 
the size of a pin’s head, creeping on the mud of stagnant ponds; in this animal 
there is a definite fore-part and hind-part, the broader end of the ovoid mass 
being in front. The figure represents the capsuled animalcule ( Arcella ), common 
in pools, especially where there is bog-moss. The brown horny shell is marked 
orange-coloured protomyxa (magnified 140 diameters). 
with a finely faceted pattern, and is shaped like a dome with a flat floor; in the 
centre of the floor is a circular hole, through which short lobose pseudopods emerge 
from the body in the interior of the dome - like box. Arcella is capable of 
secreting vesicles of air in its body-substance, 
whereby it is enabled to rise. In Euglypha 
the shell is sac-shaped, with a jagged free 
margin, and the surface covered with regular 
overlapping scales. In Difflugia the shell 
is strengthened by the addition of foreign 
particles. Amoebas are cosmopolitan; 
occurring in sea and in fresh water, and a 
few living in mosses or damp earth. Certain 
forms of dysentery are said to be due to 
amoebas, or at least to amoeba-like phases 
in the life-history of other Protozoa. 
The fungus - animals (Mycetozoa), are 
claimed both by botanists and zoologists. 
The best known species is the flowers of tan, found in tan-yards, in the form of 
large creeping masses of naked protoplasm, known as plasmodia. Cakes of proto¬ 
plasm become segregated from the main mass, and break up into amoeba-like spores, 
which again fuse to form plasmodia. 
YOUNG CAPSULED ANIMALCULE, SEEN FROM ABOVE 
(magnified), a, Fragment of Shell (magnified 
600 diameters). 
