BACTERIA OF THE STOMACH AND INTESTINE. 661 
sugar, and that Bacillus coli communis finds the most favorable 
conditions for its growth in the large intestine. 
Brieger, in 1884, isolated from faces and carefully studied two 
bacilli, one of which has since been called by hisname. This is a 
non-liquefying bacillus which is very pathogenic for guinea-pigs, 
and which in its morphology and characters of growth closely re- 
sembles the Bacillus coli communis of Escherich. Indeed, a num- 
ber of non-liquefying bacilli, differing but slightly in their morpho- 
logical and biological characters, have been obtained by various 
investigators from the alimentary canal of man and the lower ani- 
mals, and it is still a question whether they are to be regarded as 
distinct species or as varieties of the ‘‘colon bacillus ” of Escherich. 
The bacillus obtained by Emmerich from cholera cadavers in Na- 
ples belongs to this group, and, if not identical with the colon bacil- 
lus, resembles it so closely that its differentiation is extremely diffi- 
cult. Brieger’s bacillus forms propionic acid in solutions containing 
grape sugar. A second bacillus obtained by him from the same 
source resembles the ‘‘ pneumococcus” of Friedlander ; this causes 
the fermentation of saccharine solutions, with production of ethyl 
alcohol. 
Bienstock (1883) isolated four species of bacilli from normal feces, 
two of which are comparatively large and resemble Bacillus sub- 
tilis in their morphology and in the formation of spores. A third 
species is described as an.extremely slender pathogenic bacillus, re- 
sembling the bacillus of mouse septicemia. The fourth species is an 
actively motile bacillus which forms end spores, causing the rods to 
have the form of a drumstick. This is said to cause the decomposi- 
tion of albumin, with production of ammonia and carbon dioxide. 
Later researches do not sustain Bienstock’s conclusion that the ba- 
cilli described by him are the principal forms found in normal feces. 
Among the species encountered by Escherich, in addition to those 
mentioned above (Bacillus coli communis and Bacillus lactis aéro- 
genes), are the following: Proteus vulgaris, found three times in 
meconium, and constantly in the faeces of dogs fed upon flesh ; Strep- 
tococcus coli gracilis, found in meconium, but not during the period 
of nursing, is constantly present in the intestine when a flesh diet is 
employed. 
The intestine of carnivorous and omnivorous animals contains a 
greater number of bacteria than that of the herbivora, and in the 
large intestine they are far more numerous than in the small intes- 
tine (De Giaxa). Sucksdorf has enumerated the colonies developing 
from one milligramme of feces from individuals on mixed diet. He 
obtained an average of 380,000 from a series of observations in which 
the maximum was 2,300,000 and the minimum 25,000. 
