Notes on some Microscopic Organisms. 
29 
considerably. Soon a bending in of an inner membrane or “ pri- 
mordial utricle ” is seen to take place, and cell-division after the 
well-known method occurs, until a filament is formed exactly like 
that from which the original green sphere was projected. 
The important points, then, recorded in this paper are the 
finding of the means by which the active spherical form is converted 
into the still state previous to growth into a filament. The most 
remarkable fact, however, is the identification of this phase with 
one or more of the forms which have been hitherto classed either 
in the vegetable or animal kingdom, most commonly the latter, 
according to the prejudices of the observer. 
This note of the transformation of CEdogonium is the only one 
concerning the life-history of plants that I desire to record at the 
present time, but I have made so many detached observations very 
much of the same kind, that I wish to state that I am convinced it 
will be at some future day shown that all of the green, and some 
of the red-coloured forms similar to Euglena, and which have had 
several names bestowed upon them, are but transition states of fresh- 
water or marine Confervoid Algae. 
The second observation that I have to record is of certain 
phases in the life of animate organisms which have been commonly 
considered as belonging to the animal kingdom. But my notes 
here are more incomplete than in the case of the motile forms of 
the alga just mentioned, as it has been only within the last few 
weeks that I have seen what I am about to describe, and then only 
a few times, so that I wait for more opportunities for observation 
to confirm my experience. And here let me say that, apparently, 
the stages of change of these seemingly otherwise simple organisms 
I here record are, like the vegetable one just described, confined to 
the spring time of the year ; and even then to a very few days. 
Of course these changes cannot be supposed to take place, for 
instance, within the space of one week, and in every individual in 
a single locality ; but the changes are so rapid that it can only be 
by constant and patient observation that we may hope to see them 
occur, whilst slight modifying causes may defer or hasten the stage 
in different cases. 
It was on one of the bright days during last spring that I 
collected in one of the pieces of fresh water in the Central Park in 
New York, a mass of matter made up of vegetable and animal 
material, but containing, as I knew, that which would yield 
material for observation and study by means of the microscope. 
Observing it, then, in that way, I was pleased to find in it 
numerous individuals belonging plainly to the group of organisms 
which have been grouped together under the head of Amoeba. 
But remembering the observations of Dr. J. Braxton Hicks on the 
occurrence of amoeboid forms in certain undoubted vegetables, I 
