Medical Officers of the Army of India.
47
of a transition towards the flagellate, hæmatozoa of the rat; and on the other,
undoubted micrococci did not appear in any of my specimens until after the
lapse of 6-12 hours, and these were of diverse aspect and far less active amidst
the red discs. Alongside such later oscillating coccus-chains this spirillum
might be seen stretched and still, and obviously quite dissociated. Bacillar
rods motile or quiescent were distinguishable readily enough, and the displace
-ment of the blood-discs which they caused had not the peculiar thrilling charac
-ter here noted. ( See Plate IV, fig. 2.)
From its special aspect, its movements and behaviour with re-agents, I
infer that the organism in question is a bacterium belonging to the genus Spiro
-chæte—or in other words a flexible and unfolding spirillum, such as from its small
dimensions might be named provisionally Spirillum minor, with an habitat in
the blood of an Indian rat, where it is rare, e.g., once found in 117 individuals.
It is five to ten times shorter than the S. Obermeieri, and also slenderer.
Respecting its biological features, these also are strikingly divergent, indicating
a difference of properties and relationship to the common blood-medium.
Thus, first, under similar experimental conditions this minute hæmatophyte
does not, contrary to the pathogenetic bacterium, display any tendency to grow
in the blood after withdrawal from the body: it does not then, however, com-
-port itself like the ordinary putrefactive microphytes, but, as already stated,
after quiescence so long as watched seems gradually to decay. Next, as to
pathogenetic properties, an association with pyrexia of a relapsing type was not
demonstrated in this case: for although the rodent-host when first seen was
decidedly feverish, yet a possible cause for the pyrexia was some attendant
traumatism, and when the fever subsided it was not abruptly by crisis, but gra
-dually after several days: further, when there occurred the apparent relapse
seen in the Chart, a sufficient explanation appeared in the renewed local lesions
and general failing state of the animal, the character of the symptoms being
'septic,' and organisms in the blood not then multiplying. Such was my own
interpretation of the phenomena, but it should be noted that with subsidence
of the fever the spirilla did decline, their place in the blood being then taken
by minute granular particles and filaments; and also that soon after their re
-appearance the health again deteriorated and fever returned. The entire his
-tory was as follows:—
The rat had been brought from an unhealthy quarter of the town, alone, and it had
then a slight swelling on the back of the left hind foot, with œdema, being otherwise
vigorous and active, and grunting loudly when approached,—e. t. 101·2°: it remained alive
under observation for 38 days, during which period the blood was frequently drawn by
puncture and the rectal temperature taken: in its capture it had probably been injured,
and though seeming to recover somewhat, yet like other rats kept in similar constraint it
did not thrive, being also necessarily much harassed by frequent manipulations. Death
occurred suddenly at last, and at autopsy the blood was set, a peculiar sour smell