STREPTOCOCCI IN COMPARATIVE PATHOLOGY. 
691 
specific determination has become a matter of more serious 
importance. The present problems seem to rest in the follow¬ 
ing questions, viz.: (i) Are the streptococci which are en¬ 
countered in different kinds of lesions such as acute inflamma¬ 
tory processes, abscesses, septicaemia, and the like, different 
species, and ( 2 ) Is a single species of a pathogenic Streptococ¬ 
cus capable of producing disease in different species of animals 
or different kinds of diseases in the same species? Thus, can 
the same Streptococcus produce like inflammatory processes in a 
cow and in a horse, or can it cause, for instance, strangles in 
one horse and a'simple abscess or induration in another? 
A number of distinguished bacteriologists and pathologists 
have written concerning the similarity and even the identity of 
certain streptococci which previously were supposed to belong 
to different species. Thus, Prudden * found that the streptococcus 
which he isolated from the throats of children suffering from diph¬ 
theria could not be differentiated from S. pyogenes and A. erysip- 
elatos. Welchf placed the streptococci of erysipelas, phlegmo¬ 
nous inflammation, septicaemia, puerperal fever and various forms 
of angina in one and the same species. 
ZschokkeJ supposed the streptococcus which he isolated 
from cases of strangles was identical with A', pyogenes until 
Schiitz showed its specific relation to the disease. Hell could 
not separate A', pyogenes from A', pyogenes equi , A. erysipelatos 
and the streptococcus of Brustseuche. The list of those who have 
failed to find distinguishing characters or properties in strepto¬ 
cocci thought to be the specific cause of different affections could 
be lengthened should additional testimony on this point be 
desired. Although the evidence is strong to support the single¬ 
ness of species, or at least to reduce the number, a few observers 
have come to believe that there are distinguishable differences 
existing between these forms. 
*The American Journal of the Medical Sciences, XCVI 1 . (1889), p. 229. 
t The American Journal of the Medical Sciences, CII. (1891), p. 439. 
\ Milit-Vet. Zlschr. II. S. 97. Ref. Jahresbericht der. Veterinar-medicin, 1889. 
S. 18. 
