215 
kingdom, most commonly the latter, according to the predjudi- 
ces of the observer. 
This note of the transformation of ({dogonium 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 colored 
forms similar to Euglena, and which have had several names 
bestowed upon them, are but transition states of fresh water 
or marine Confervoid Algze. 
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 ex- 
perience. 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 fo see them occur, 
whilst slight modifying causes may defer or haibiae the 
the stage in different cases. 
It was on one of the bright days during this spring that I 
collected in one of the pieces of fresh water in the Central 
Park in this city, 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 
