47
To proceed. with the study of the various bacilli ; it will be seen that table
VII (c) goes into much greater detail, and. gives the percentage prevalence of separate
-organisms in the various series. A large number of very interesting points are
demonstrated by this table. The most striking feature is the continual and steady
presence of the Grunthal group, the coscoroba group, and, to a less extent, the coli
group. Wide variations in percentage occur however, and even entire absence of these
bacilli is recorded in some series, but these organisms undoubtedly form the bulk of
those present in dejecta of man and cattle. The main interest of this study however
lies in the presence or absence of the rarer bacilli ; in this connection much has yet to
be discovered.
Great variation, both in number and kind, occur in the flora of fœces at different
times of the year. Compare, for instance, the results of series Nos. 1 and 9 taken in
July 1908 and March 1909 ; note the very rich mixture in the human fœces in No. 1
and the few varieties in No. 9. Observe the relative number of coli communis in the
two series ; also the number of cloacæ and the number of coscoroba. The changes
noticed to some extent apply to both human fœces and cowdung. Both human fœces
and cowdung show a considerable falling off in coli communis and in cloacæ, on
the other hand, both show a very great increase in such organisms as coscoroba.
Another most striking example of the rapid change of the flora of the intestine of man
and animals is to be found in series No. 5. This change is not so much in quantity
as in quality. It has been pointed out in Chapter No. V that a change came over the
bacteria found in the water-supplies, when certain natural conditions obtained. Subse-
quently it was noticed, that, at this time, a similar change had occurred in faces, not
.only of animals, but of man. For some entirely unknown reasons, a group of organisms,
which up to this time had been extraordinarily rare, were found in large numbers in
the feces of cows, goats and men. This subject has already been discussed in another
place ; but the point we wish to emphasize is, that, natural forces exist, of which we
know practically nothing, which, are capable of causing alteration of the flora of the
intestinal tracts of animals and men.
It is usual to find, that, if a change in the bacterial contents is observed in the
faces of human beings, a similar change is also found in those of domestic animals.
We consider, speaking broadly, that table VII (c) bears out this. The falling off
in the number of coli communis in both cattle and human fœces in March has been
already pointed out. The mere figures do not represent how great is the change.
We have sought through dozens of samples of human fœces and cowdung, in order to
find one specimen rich in coli communis without success. In July and August 1908
. about one sample in four was crowded with these organisms.
Note the presence in large numbers of cloacæ in cowdung in series Nos. 1 and 2,
the smaller numbers in human fœces, followed by their absence from series Nos. 3, 4,
5 and 6 in human fœces, their absence from cowdung in series Nos. 3, 4, 7, 8, and
the reduced numbers in Nos. 5, 6 and 9.
Observe the steady increase in the numbers of coscoroba in both human fœces and
cowdung.
The presence of organism No. 67 in fair quantity in series 1, in both human fœces
and cowdung, and its disappearance from nearly all other series, is also significant.
We do not wish to push this too far because it cannot be said to be an absolute
.rule ; but from experience in the laboratory we are prepared to state that
(1) there appear to be seasons when certain organisms are commoner than at
other times ;
(2) that when an organism is found commonly in cowdung it is nearly always
present, though not necessarily in the same quantity, in human fœces ; and
(3) that it is usual to find the same organism in the water-supplies at the time.
In support of this latter statement we wish to draw attention to tables XIII (a), (b)
and (c), Chapter XIII, where it will be observed for the quarter July, August and
September bacillus cloacæ was fairly common in river water, very common in lakes,
springs and wells. Analysis of human fœces and cowdung during the months of July
. and August also show a marked prevalence of this organism. Similarly in the second