DIGESTION OF FOOD. 317 
occur in pancreatic digestion, both within and without the 
body, they are to be regarded as accidental, for by proper pre- 
cautions digestion may be carried on in the laboratory without 
their occurrence, and they vary in degree with the animal, the 
individual, the food, and other conditions. It is not, however, 
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Sy \\l ty NR SRE ye 
Fie. 271.—Micro-organisms of large intestine (after Landois). 1, bacterium coli cummune ; 
2, bacterium lactis aérogenes ; 3, 4, large bacilli of Bienstock, with partial endogenous 
spore Soumnsion ; 5, various stages of development of bacillus which causes fermentation 
of albumen. 
to be inferred that micro-organisms serve no useful purpose 
in the alimentary canal; the subject, in fact, requires further 
investigation. , 
Succus Entericus.—The difficulties of collecting the secretions 
of Lieberkiihn’s, Briinner’s, and other intestinal glands will be 
at once apparent. But by dividing the intestine in two places, 
so as to isolate a loop of the gut, joining the sundered ends by 
ligatures, thus making the continuity of the main gut as com- 
plete as before, closing one end of the isolated loop, and bring- 
ing the other to the exterior, as a fistulous opening, the secre- 
tions could be collected, food introduced, etc. 
But it seems highly improbable that information approxi- 
mately correct at best, and possibly highly. misleading, could 
be obtained in such manner. Moreover, the greatest diversity 
of opinion prevails as to the facts themselves, so that it seems 
scarcely worth while to state the contradictory conclusions 
arrived at. 
It is, however, on the face of it, probable that the intestine 
—even the large intestine—does secrete juices, that in herbiv- 
ora, at all events, play no unimportant part in the digestion 
of their bulky food; and it is also probable, as in so many 
other instances, that, when the other parts of the digestive 
tract fail, when the usual secretions are not prepared or do not 
act on the food, glands that normally play a possibly insig- 
nificant part may function excessively—we may almost say 
vicariously—and that such glands must be sought in the small 
intestine. There are facts in clinical medicine that seem to 
