INFUSORIA. IOI 
vacillating manner. The globule is formed of a homogeneous trans- 
parent substance, which throws out obliquely a whip-like filament, 
three, four, or even five times the length of the body of 
the Monad. 
The genus Cercomonas of Dujardin has its body pyri- 
form, having in front a vibratile filament, very long, very 
flexible, and easily agitated. Behind the body there is a 
thicker straight filament attaching itself sometimes to 
neighbouring corpuscles, round which, in this case, the 
Cercomonad oscillates like the ball of a pendulum round i oy. 
its stem. Monas lens 
The £uglenea are infusoria usually of a green or red alata 
colour. Their form is very variable. They are oblong 1,00 times. 
or fusiform in shape, swelling at the middle during loco- 
motion, and contracted or bowl-shaped in repose, or after death. 
They are furnished with the usual whip-shaped filament, which issues 
from an opening in front, and pos- 
sess one or many reddish points ae 
irregularly placed anteriorly. gi al le ho, 
Luglena viridis (Fig. 35) is the . 
most common species, and among 
the most widely diffused of all the 
Infusoria. It is this animalcule 
which is often met covering stag- 
nant pools with a floating surface 
of green, and which forms, on the 
surface of marshy waters the shin- 
ing pellicle so strongly coloured, 
which, collected upon paper, so 
long preserves its brilliant tint. 
The Zuglena sanguinea, at first 
green, becomes subsequently of 
a blood colour. It has often 
‘been met with by microscopists. 
Ehrenberg, who first described , - 
it, attributes to its great abun- _ LF 
dance the red colour of some ~ »# 
stagnant waters. Its presence 
may perhaps explain the pre- 
tended miracle of water changing 
into blood, which was frequently ' 
invoked by the Egy ptian priests. Euglena viridis (fh cagnified 350 times. 
