el eee a itil 
—=- - = 
490 
been added. This type can be distinguished from the fourth one in that 
after twenty-four hours, it gives an acid reaction on a culture medium 
containing mannite but this gradually disappears until finally, after 
four days, the medium becomes alkaline and remains so. Therefore this 
type is a form intermediary between the acid and non-acid dysentery 
bacilli. 
The agglutination phenomena of these five groups of dysentery bacilli 
on the whole agree with the fermentative action on mannite and the other 
carbohydrates. The rabbit yields a specific immune-serum against the 
different types of the organism, and therefore this animal is recom- 
mended for carrying on the experimental work; the goat, on the other 
hand, frequently does not give a specific immune-serum, and hence can 
not be employed to so great an advantage; and finally, the immune-serum 
to be obtained from the horse is useless for this purpose, as it generally 
gives an unreliable group reaction. Types I and V form the two end 
points in the agglutination phenomena; each immune-serum obtained by 
their use has a specific but no common reaction, or, in other words, neither 
one has agglutino-receptors common to the other. Types IH, II, and IV 
show a gradual transition from one extreme to the other. (See Table 
IV.) The bacteriolysis brought about by the rabbit immune-serum is 
also not a strictly specifie phenomenon, because the serum of one group 
frequently exerts more or less of an action on the others. 
If all of the experiments outlined above are taken into consideration, 
it finally becomes evident that the total results of the fermentation of 
carbohydrates, the phenomena of agglutination and those of bacteriolysis 
are not only not entirely in accord but that they even are somewhat con- 
tradictory. Therefore, from the data at hand it seems to me impossible 
to arrive at a final classification, and consequently, lacking a better one, 
I will, for the present, retain the division into five groups which I have 
outlined; a discussion of another system arising from the standpoint of 
serum therapy will be entered into below. 
TILE OCCURRENCE OF SPECIAL TYPES OF DYSENTERY BACILLI ENCOUNTERED 
IN DIFFERENT EPIDEMICS. 
As has been shown above, other varieties of dysentery bacilli (para 
dysentery bacilli) exist in addition to the one which was first discovered, 
and these forms, as well as the one originally described, are etiological 
factors in the causation of the disease, so that the important question 
as to the relationship between the first and the subsequent varieties was 
at once forced upon us. In order to find the answer, the occurrence of 
the various types of dysentery bacilli in their epidemological behavior 
was studied, to accomplish which end I obtained many cultures of the 
organisms from various provinces and countries and subjected them 
all to exact study. The bacillus which was first described by me was 
encountered in by far the greater percentage of cases among dysentery 
