INFUSORIA. 
21 
On the surface of stagnant ponds may often be seen, 
especially in spring, a stratum of what looks like a bright 
green powder. If a small quantity of this be taken up 
and examined, many curious and beautiful forms will be 
discovered. A large portion of the substance will pro- 
bably consist of different species of the genus Euglena — little 
active creatures, somewhat resembling fishes in shape, of 
a rich green hue, with a large red eye. Among them we 
may find what is sometimes called the High-priest’s 
Breastplate ( Gonium pastorale), consisting of sixteen oval 
green masses, disposed regularly in a transparent shell of 
square form, like emeralds set in a plate of the purest 
glass. Another brilliant casket of gems is the Pandorina 
morum (Plate I. fig. 2), a species which we have taken in 
the neighbourhood of London. It is a crystal globe en- 
closing about thirty globose animals of a rioh green hue, 
from each of which proceeds a long, whip-like proboscis, 
about as long as the radius of the globe. By means of 
these filaments it proceeds rather quickly, rolling over in an 
irregular manner as it goes. Its appearance is very rich 
and beautiful, particularly when the light is transmitted, 
as it sometimes is, through the interstices of the animal- 
cules, and gleams through their dark-green bodies. The 
newly-invented paper-weights, consisting of balls of solid 
glass, in which are imbedded some beautiful coloured 
objects, will give an idea of this creature. 
Many kinds are interesting from the close resemblance 
m form which they display to other well-known objects, 
animate or inanimate. The Volvox (fig. 3) rolls majesti- 
cally through the water, revolving regularly on its axis 
like an artificial globe ; and as it is of greatly superior 
