234 BACTERIA. 
candidum would grow deliquescent with age. Subse- 
quent culture, however, showed the spot to consist of a 
mixture of various species, requiring different terms of 
incubation. 
A culture made from this on March 12, developed a 
luxuriant, bright yellow, semi-fluid growth consisting of 
broadly oval cells in a gelatinous substratum. This 
soon spread over the surface of the potato and grad- 
ually assumed greater consistency until it was like soft 
wax. 
This form was under my observation about a month, 
yet never in any culture developed the characters of 
either B. aurantiacum or B. luteum. ‘Though the cells 
are ellipsoidal, rather than spherical, they are not at all 
slender, and as fresh cultures developed the same cells, 
I cannot believe them to be the gonidial stage belonging 
to B. lutewm. 
Bacterium candidum, Trelease. This species appeared 
very frequently so that it was difficult to exclude it from 
other cultures. Even when glasses were treated with 
corrosive sublimate, and needle point and knife were 
scrupulously fired before making an inoculation, it 
would develop and quickly overrun the rarer forms. 
It is an interesting species on account of the various 
phases in the development of its external characters. 
In twenty-four hours after its inoculation, it forms a 
white, glistening, opalescent growth upon the surface of 
the culture medium. In the next stage, this surface is 
dulled, and a delicate white film is rapidly formed. 
This by degrees becomes slightly roughened until the 
surface seems sprinkled with a fine, snow-white pow- 
der, and a hand-lens shows that this appearance is due to 
a fine lobation of the surface. Now the zooglea is 
thickened and begins to wrinkle in characteristic folds, 
while the color deepens to a creamy color and finally to 
a brown. 
118 
