Medical Officers of the Army of India.
by Mr. Steel) must now be interpreted as in a special degree significant.
To the best of my recollection, none of the hmatophytes are harmless tenants
of the blood, all being possessed Of pathogenetic properties and all, moreover,
belonging to the fungus- (or alga-) group of schizomycetes : whereas no such
uniformity of property, or of classification, obtains amongst the known haæmatozoa,
and hence of these an important differentiation -may and has now to be made.
Thus, on the one hand, there are the familiar instances of high-grade vertebrates
whose blood teems with large and active organisms, without for a time at least
any very manifest prejudice to their own health, —these instances, e.g., of birds
and many mammals (reptiles and fishes are not excluded) being sometimes quoted
in. support of the view that all organisms appearing in the blood have but a
subordinate Meaning : and on the Other hand there is the instance of this
" surra " disease, in which according to concurrent testimony the horse or mule
in whose blood minute organisms . appear; of far less formidable aspect than
embryo-worms; is doomed to death if less quickly not less surely than an
equine infected with the bacillus of anthrax. Limiting attention to these
contrasted data, a reasonable explanation of the pathological differences herein
noted, ml i g h t , I
t h i n k , b e
f o u n d
i n - t h e c i r c u m s t n c e t h a t . e m b r y o T r e m a t o d e s a n d
Nematodes make use of the circulation chiefly, if no wholly, as a means of
transport, neither developing nor even growing larger therein—the persistent
egg-sac of some being a palpable bar to all but simplest nutritive interchanges ;
mor e ove r , t he s e f i l a r i æ r e ma i n but t r a ns i t or i l y wi t hi n t he bl ood- ve s s e l s , be i ng
probably after a few hours either destroyed Or extruded, in neither of which
processes is there a conceivable necessity of serious impairment being done to
the constantly replenished and purified blood. Some deterioration of the
inhabited media is, indeed, inevitable if not demonstrable ; and account must
be taken of the mechanical lesions occasionally (at least) resulting from impac-
tion Of the worm-parent Or offspring in the blood and lymph channels of the
hosts' body, with consequent œdema and hæmorrhage, either interstitial or
free: yet upon consideration it will be evident enough that all such series of
morbid changes are of a totally different character to the profounder alterations
characterising veritable blood-infections; and could not lie deemed reproducible
in healthy subjects by inoculation of a. blood-drop, as may be the " surra " and
anthrax diseases entire.
The last topic have to allude to is the remarkable contrast of symptoms
offered by the rodent and the equine when their blood is equally infested by
an organism Morphologically identical in the two cases : thus, as already de-
scribed; the rat-'then appearing to be altogether unaffected in its health, whilst
the horse or mule suffers greatly and is certain presently to die, So far as
I am aware, there is not known any strictly similar instance to this amongst the
h æ m o p h y t i c i n f e c t i o n , n o r a n y s t r i c t l y a n a l o g o u s a m o n g s t t h e h m o p h y t i c :
yet upon analysis and comparison of all the data, it seems to me that the
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