DESCRIPTION OF PLATES. 137 
case of other diseases it may be said that much 
more has been claimed than has been proved. The 
whole question is still under investigation, and it 
would be premature to express a positive opinion 
as to the vé/e of these organisms in the diseases in 
question, except as regards those diseases of ani- 
mals in which it has been definitely established 
by the experimental method, — fowl-cholera, and 
septicemia in rabbits. 
Those who desire fuller information concerning 
the Bacteria, are referred to the writer’s transla- 
tion of Magnin." 
UNICELLULAR ALGw#. (Puate III. Fie. 1.) 
The group from nature seen in Plate III. Fig. 1, 
is quite a model one for showing the mode of 
division of a unicellular organism undergoing 
rapid multiplication by spontaneous fission, — binary 
division. 
Every step in the process can be traced by 
referring to different cells, from commencing 
transverse division in one direction to complete 
division with commencing fission — at a right angle 
with the first line of division — in each cell of the 
pair. 
The Micrococci are, according to Cohn, the dis- 
tinguished German botanist, unicellular alge, al- 
though Néageli and others class them with the 
Fungi. The chief distinction between these two 
classes of cryptogamic plants consists in the fact 
that in one (the Alga) the green coloring matter 
1 The Bacteria. Boston: Little, Brown, & Co. 1880. 
