INVESTIGATIONS OF THE BUREAU OF ANIMAL INDUSTRY. 631 
cavities, that it can often be detected only with the plate cul¬ 
ture method. To these differences enumerated by Frosch, 
we may add that the hog cholera germ is most frequently 
seen in pairs when cover-glass preparations from the organs 
}f the affected animals are made, while the swine plague germ 
.rnder the same conditions is generally single. 
I have summarized these points of difference Irom Frosch’s 
Daper in order to ask if it is possible for any bacteriologist to 
nistake one of these germs for the other after he has studied 
hem in cultures and by inoculating animals with them. And 
/et to assume such a mistake is the only wav in which we can 
larmonize the germs sent by Billings to Koch, with the de¬ 
scription in the former’s reports. 
I am aware that some of the statements in his reports indi¬ 
cate that the hog cholera germ was under investigation, while 
)thers would indicate that it was the swine plague. For in- 
tance, the statement that he watched the development of the 
'erms in a hanging drop culture would be absurd applied to 
he actively-motile hog-cholera germ. Frosch tried to follow 
lim in this, but gave it up as impossible. On the other hand, 
he luxuriant growths on potatoes which he described could 
tever come from the swine-plague germ. Again, the first cul- 
ures which he sent to Europe are said by Bunzl-Federn to 
ave developed acidity in milk cultures, and to have formed 
ihenol and indol, which shows them not to have been the 
og-cholera germ, while later he undoubtedly sent the hog- 
holera germ to different investigators. If we accept these 
arious statements of fact we can only conclude that he at 
ne time had one germ and at other times the other germ ; 
ideed this is indicated by his inoculation experiments, in 
, 7 hich some of the animals died too soon for death to be 
aused by the hog.cholera germ, and others after too long a 
eriod to indicate the swine-plague germ. 
It is no task of mine, however, to explain his inconsisten- 
iesand contradictions. I should not have taken the trouble 
) point them out had his work not been held up to this 
association in connection with Frosch’s report, in the attempt 
p show the report of the Bureau of Animal Industry to be 
