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This multiplication by fission, in an average of forty cases, was 
completed in four minutes and forty seconds, and continued to be 
repeated without variation during from two to eight days. 
After this period the organism gradually assumes an ameeboid 
form by pouring out a delicate sarcode, and moves only by pseudo- 
podia although the flagella are still present and somewhat active. 
In the course of seven hours, there were several of these amceboid 
forms in the field, each enclosing or enveloping a flagellated body. 
Finally two of these approached each other until they touched, 
and rapid blending of the sarcode took place, the flagella disap- 
peared, the bodies came in contact with each other and rapidly 
coalesced, and the common body thus formed increased in size 
until it was no longer enveloped in the delicate sarcode, but be- 
came a mere, smooth, globular cyst with a distinct integument 
which afterwards became thin, burst, and discharged a viscid 
mass of oily looking matter. Under the power employed, Powell 
and Lealand =; and A ocular (X 2500), this presented, when 
somewhat dispersed, a minutely granulated appearance. By 
adding an eight inch drawtube and B ocular, it became certain 
that this consisted of a densely packed mass of inconceivably 
small granules. The observers believe that they should have 
wholly failed to see these sporules but for their enormous aggre- 
gation and motion in a mass, and that ‘‘ with the 3; the most accu- 
rate observer could not have discovered their presence if he had not 
previously seen them with the 5.” j 
he development of these granules was now watched with the 
greatest care. In six hours they had increased to a decidedly 
perceptible degree, though still far smaller than the minute and 
familiar Bacterium termo of Cohn; an hour or two later they 
began to reassume an oval shape; in nine hours from the first they . 
had become rather larger than B. termo and had become flagellate 
and begun to move freely, the bodies became vacuolate, and in 
something less than twelve hours the normal parent form was 
assumed. This history was traced carefully and repeatedly, and 
with unvarying results. 
The effects of heat and dessication were also tried ; and it was 
found that although drying slowly upon a glass slide and exposure 
to a dry heat of 121° C. entirely destroyed all the adult forms, 
yet, after moistening again with distilled water and watching the 
field for some hours, growing points were in some instances dis- 
