ISABEL MULFORD. 233 
but they were so extremely minute that I do not feel 
justified in making a positive statement. 
Micrococcus aurantiacus, Cohn ; Bacteridium auran- 
tiacum,Schroter. This species developed spontaneously 
upon the white of a hard-boiled ege placed under an in- 
verted tumbler after a few moments exposure to air. It 
was first observed in about twenty-four hours afterward 
in the form of minute yellow dots. These grew to the 
size of a small pin-head, and multiplied in number until 
‘they became nearly confluent over a surface of about a 
square centimeter. The color was a bright, golden 
yellow, soluble in water. 
Microscopic investigation showed these zoogla@e to 
consist of oval cells 1.5 in their longer diameter. 
Orange-colored zooglaw@e having micrococcoid cells 
were also observed upon potatoes, but as cultures from 
these sometimes developed elongated, sometimes micro- 
coccoid-oval cells and usually a mixture of both forms, 
I am in doubt as to whether my cultures were pure, or 
whether one form developed from the other. 
Micrococcus luteus, Cohn ; Bacteridium luteum, 
Schroter. A potato whose cut surface was touched to 
the sink of the mineralogical laboratory January 16, 
quickly developed luxuriant growths of Bacterium 
candidum and B. lutewm each occupying about equal 
halves of the potato. This culture I kept a long time 
to see whether either species would overpower the 
ather. £8. candidum at last spread over the outside of 
the potato, and penetrated tender or broken places in 
the skin. 
B, luteum maintained its early position with reference 
to the other species mentioned but was not able to ex- 
elude other growths. 
During the second week a small, smooth, reddish- 
brown spot appeared in its midst, which I at first imag- 
ined was an indication that this species as well as B. 
st a7 
