Page 103 - My FlipBook

BIOLOGICAL STUDIES ON THE BACTERIA OF THE MOUTH. 77

cases, and used all possible kinds of nutrient media, I did not suc-
ceed in produeino* the slis^htest o;rowth of this funous. On ijela-
tine and agar-agar with beef-extract, calf's broth, and beef-water-
peptone, saliva, etc., also in fluid media at various temperatures,
no development ever took place.
This fact alone is quite sufficient to establish the total differ-
ence of the organisms under consideration from the cholera
bacillus, which, as is well known, grows very well on artificial
culture-media. It is, however, to be hoped that a pure culture
may yet be procured, since it is in itself an organism of great
interest. But Spirillum sputigenum is not the only fungus occur-
ring in the human mouth which produces curv^ed rods. Another
kind, not difficult to cultivate, occurs in
short, plump, tapering rods, generally united Fio 25.
in pairs, some of which show a slight cur-
^jp^
vature (Fig. 41); this is particularly observed » /* o}^^ o o
in rods undergoing fissation. This bacterium ^ o,l ''
\J
is motile, grows well at room temperature,
and quickly liqueiies the gelatine.
A third mouth-l)acterium, which I have „ ^ T
' Halp-Circclar Rods
already described in the Independent Prcu- from a Ccltcre of
''"" ^^acillus
titioner'^ and in Xo. 36 of the Deufsrhe med.
OF Miller.
WoeJtensrJii'., 1884, occurs in the form of iioo:i.
delicate rods of varying length, sometimes
straight and sometimes so curved as to form the arc of a circle,
two rods together making the letter (Fig. 25). The cells var}'
in form to such an extent that I first supposed I had an impure
culture before me ; the attempt to separate them, however, did
not succeed. Later, on observing various forms on one thread
(Fig. 25, f), I became convinced that they belonged to the same
fungus. The rods show every degree of curvature, from the
straight to the semicircular. Two united rods sometimes form
an S-, more frequently an 0-shaped figure; in some cases the
rods are so combined that they are scarcel}- distinguishable from
cocci (Fig. 25, b). By the fissation of the rods, chains of cocci are
formed, as is best seen in old cultures. No formation of spores
was observed, and, examined in a hanging drop of bouillon, the
rods displayed no motion.