626 
D. E. SALMON. 
points of resemblance found in the description of the hog 
cholera germ given by Frosch and in the description con¬ 
tained in the Bureau reports for 1885 and 1886. I will, how¬ 
ever, enumerate the principal ones. The form and dimen¬ 
sions are given as exactly the same, 1.2 to 1.5 yu long by .6 yuin 
breadth, both stating that they are liable to variation under 
different conditions. Both state that they are found in the 
blood and tissues, oftener in pairs than single ; that while they 
stain readily by the usual solutions of aniline substances, the 
staining by Gram’s method is unsuccessful; that they are ac¬ 
tively motile in fresh cultures; that they grow upon the acid 
surface of the potato ; that they do not liquefy gelatine, and 
that the gelatine colonies are brownish disks, often having a 
dark center which makes them resemble a nucleated cell; 
that they grow upon the usual culture media in both room 
and incubator temperatures, presenting in each case the same 
appearance ; that the time between inoculation and death is 
longer than with other septicasmic diseases; that in small 
animals it causes but slight local reaction; that mice, rabbits 
and guinea-pigs were very susceptible, while pigeons require 
a dose of about 1 cc. to produce fatal results, and chickens are 
insusceptible ; that in pigeons the pectoral muscle, on the side 
of the inoculation, assumes a parboiled or cooked appearance, 
while in inoculated mice and rabbits the liver becomes 
enlarged and presents numerous foci of coagulation necrosis. 
In addition to the above, each author has mentioned some 
points which he considered of value, but taking simply the 
points which harmonize, we have a picture which clearly dif¬ 
ferentiates this germ from any other known micro-organism, 
and which is amply sufficient for its identification. Frosch, 
himself, says after giving the results of his examination of the 
culture sent by Billings: “ If one now compares these results 
with the description of the Salmon hog cholera bacterium, 
then such a similarity of the two bacteria in the main points 
of morphology and biology is found that their identity cannot 
be doubted, and it would be superfluous to again enter more 
closely upon the individual points in which they correspond.” 
If Frosch is correct in this opinion, and no one who has 
