Medical Officers of the Army of India. 6 7
Here what is known is, first, the co-presence in the blood with abounding grown
organisms, sometimes clustering or blending, of numerous small motile particles
and frequent cyst-like forms which have the aspect, at least, of reproductive
elements at various stages of development, and which nearly all observers have
noted (see Dr. Crookshanks figures and some of mine): add, also, that whilst
obviously plentiful growth must take place somewhere in the rat and horse's
body, hitherto outside the blood no parent-source of the parasite has been
detected. Mr. Steel's successful inoculation with fresh blood, in which at the
time no parasites were detectable, is quite noteworthy and corresponds with some
experience of mine when studying the relapsing fever of man, the explanation
being either that grown organisms had (as is possible) been overlooked, or that
the new brood had sprung from germs contained in the blood (as also seemed
likely in one of my cases). The second point to note is concurrent testimony
regarding the advent of the hæmatozoon by intermittent succession of broods.
I had not actually seen this in the rat, but apparently it was so in a healthy-
looking dog in the possession of Dr. Lewis; and as regards the "surra"
i n f e c - t i o n D r . E v a n s h a d n o t i c e d i t s p r o b a b i l i t y , w h i l s t M r . S t e e l h a s f u r n i s h e d
definite affirmative evidence in both natural and imparted disease. Analogous
thereto are the events in the human recurrent spirillar infection; only here the
malady tends to subside by diminution and delay of the relapses, whilst equine
relapsing fever seems always to end fatally. Whatever prove the future explana
-tion of this significant phenomenon, it will apply to both these kinds of blood-
infection, and may apply also to the malarial, typhoid, and certain septic
species. Lastly, I have to notice the fact that, so far as known, the hæmatozoon
is not only limited to the blood-area, but is equally diffused throughout it, and
the same datum was clearly ascertained for the spirillum of relapsing fever, by
comparative scrutinies of blood taken immediately after death (of infected
monkey) from each of the principal regions and viscera of the body.
Before quitting this part of the subject, there might be mentioned certain
seeming counterfacts to some of the propositions above surmised. Thus, as
regards evanescent quality of the hæmatozoon, this would appear less marked
than is stated of monads generally; Lewis in particular having remarked that
the rat's organism was not very sensitive to the action of mercuric perchloride,
whilst according to Leuckart this salt has in general such a prompt destructive
action that its employment therapeutically seems to be indicated Again, Mr.
Steel once failed to propagate the "surra" disease by administration per oram
of the gastric and intestinal matters of a diseased mule: and, further, what
seems adverse to the asserted persistency of monad-germs, the subcutaneous
injection of dried tainted blood also failed. Dr. Evans, too, found on two trials
no effect after the swallowing of a water-mixture containing infected blood
which had been kept for 24 hours and without signs of putridity no longer