144 PHOTO-MICROGRAPHS. 
EUGLENA virIpis. (Puate III. Fie. 2.) 
The curious unicellular organism of which we 
have a photograph in Plate III. Fig. 2, resembles 
the Algz in having a bright-green color, — not, 
however, in the form of granules, but distributed 
through the ‘‘endoplasm,” so as to give it a uniform 
green tint, even when examined with the highest 
powers. This green coloring matter seems to be 
similar to, if not identical with, the chlorophyl 
of plants; and the organism in question is classed 
with the unicellular Algae by some naturalists, 
while others place it with the Infusoria, — the 
lowest animal organisms. 
Dr. Carpenter says: “If, as appears from the 
recent observations of Biitschli, the well-known 
Astasia — of which one species has a_ blood-red 
color, and sometimes multiplies to such an extent 
as to tinge with it the water of the ponds it inhab- 
its —has a true mouth for the reception of its 
food, it must be regarded as an animal, and sepa- 
rated from the Euglena (with which it has been 
generally associated),— the latter being pretty 
certainly a plant, belonging to the same group as 
Volvox.” 
On the other hand, Kent, the latest and highest 
authority upon the Infusoria, describes the Euglena 
as “ free-swimming animalcules,’ and presents evi- 
dence to show that they have an oral aperture. 
He says: “The apparent absence of a distinct oral 
apparatus and ingestive cavity, taken together with 
the green hue of the body-plasma, previously 
