116 Germ of the Southern Cattle Plaque. 
about 4 the transverse diameter of a red-blood cell, in length. In 
one way, however, they can be easily differentiated even by micro- 
scopic examination. The swine-plague germ has a far sharper afin- 
ity (its poles) for the blue and violetHinctions than that of the Southern 
Cattle Plague, while the tatter pussesses a special affinity for Fuchsin, 
which the former does not. Whatever the tinction used, if applied 
lege artis, the ends, poles, of these micro-organisms show a great 
specific affinity for the coloring material, while the middle portion of 
their bodies has far less, unless the exposure is pushed to a longer 
period, when this portion of the body will eventually color. The 
capsule of these germs seems to be composed of the same material 
as the ends, as it also colors in the same manner, thus presenting a 
delicate line of colored material, connecting the two colored, coc- 
coid ends, or poles. 
The most practical illustration which can be given of the micro- 
scopic appearance of these organisms, is to take a small white bean 
and paint both of its ends and two of its sides blue or red, leaving 
the middle portion unpainted. Looking down upon such a bean 
would give almost an exact picture of these germs. 
Like the genuine and only germ of the American Swine Plague 
the micro-organism of the Southern Cattle Plague is motile in fluid 
cultivating media when studied microscopically, as well as in the serum 
from the blood of diseased animals. The movements of the latter 
are, however, less rapid or active than those of the former organism. 
In my earlier description of the micro-organism of the American 
Swine Plague, I called attention to the great morphological varia- 
tions which it undergoes in its full cycle of development. These 
are its morpho-vegetative phenomena. 
To one entirely unaccustomed to observing them, the first appear- 
ance of a cultivation of these germs—more especially an old one— 
would prove very puzzling. In fact, the novice would very often 
conclude that his cultures had become polluted by micrococci, so 
plentifully are these objects, apparently, represented. They simply 
represent a vegetative, embryonic, period in the development of this 
class of micro-organisms. 
1For some, to me, unaccountable reason the German observers say 
the germ of the German Swine-Plague isnot motile and Cornil says the 
same thing. Now I positively assert the micro-organism of these two 
American diseases to be motile as well as a third one which I am not yet 
ready to describe. 
