ISABEL MULFORD. 231 
ing forms of grouping. They are spherical and measure 
.7-.9 in diameter. 
Micrococcus, species d. <A slice of potato rubbed on 
the wall of a side room in the barn, developed in a few 
days a small patch of pink color. At first this was bad- 
iy mixed with mucors and other weeds, but after a few 
inoculations these were excluded and the bright pink 
zoogloea succeeded in establishing itself as an indepen- 
dent growth of great vitulity. This species was under 
my observation for over a month and during that time, 
many cultures were made, all showing the characters as 
described below. 
The zooglaa shows a decided growth, visible to the 
naked eye within twenty-four hours after inoculation. 
It forms little conical masses along the line touched by 
the needle in inoculation. These are quickly confluent, 
and the growth soon spreads over the entire cut surface 
of the potato, and then extends downwards through the 
substance until the whole massis deeply colored. If the 
lower side of the potato is cut, a thick growth appears 
there also, but the zoogloea does not penetrate the skin. 
The color is at first a beautiful tint of pink, but in two 
or three days the exterior portions become duller while 
the color is intensified below. The zooglaa has a semi- 
solid, waxy consistency. In growth, a slight fermenta- 
tion is apparent, and the surface is raised in places, 
forming a pellicle over the bubbles of gas beneath, thus 
giving a blistered appearance to the potato. The raised 
part is quite thick, and never transparent or membra- 
nous. A bright orange or amber-colored zoogloea was 
occasionally seen associated with this form. As the J/. 
prodigiosus is described as varying in color, I at first 
thought I had perhaps encountered that species, but 
I never saw one color develop from the other. If I 
transferred the orange, it developed an orange zooglo@a, 
if the pink, the resulting growth was pink. As before 
aS 
