STUDIES UPON AMOEBA 
311 
III. THE LIFE CYCLE IX AMOEBA 
A. Ainoeba proievs (?) 
At the mid-winter meeting of the American Society of Zoologists 
in 1907. a paper of mine was read, describing briefly the formation 
of flagellospores in Amoeba, and their behavior in sexual repro- 
duction. This paper was not published at that time. The obser- 
vations were first made at the Woman's College of Baltimore in the 
spring of 1905, and would have been published more promptly 
had I not been somewhat uncertain whether the phenomena 
belonged to the life history of Amoeba or to that of a parasite of 
Amoeba. Further study convinces me that we have in these 
phenomena a true sexual process of Amoeba itself. The work is 
not yet completed, but I will no longer delay publishing an outline 
of the observations. 
In the valley of the Patapsco river, near Baltimore, there is a 
small, never-drying spring, in which, and in whose outflowing 
streamlet, one rarely fails to find very abundant Amoeba proteus. 
In the spring of the year 1905 I collected a large quantity of mud 
and leaves from this spring and stream and placed it in an aquar- 
ium, intending to divide the material later into several parts, so 
as not to overstock the aquaria. This, however, was neglected 
and after about a week the aquarium was very foul and evil smell- 
ing. Casually examining the scum that covered its surface, my 
attention was drawn to certain very peculiar Amoebae of exceed- 
ingly minutC size, that occurred in countless millions all through 
this surface scum, the whole field of the microscope being filled 
with them. 10 
Perhaps the most strikingly interesting forms were such as the 
one drawn in fig. 34 (magnified 1700 diameters). In such individ- 
uals the major part of the body was usually in a more or less 
globular mass, from one or more places upon which a few pseudo- 
podia, composed mostly of ectosarc, procruded. These pseudopo- 
" I have since found these Amoebae equally abundant in material collected from 
each of half a dozen other localities. 
