98

Report on Kála-ázar.

demand for red corpuscles. This change I have found to
be a characteristic and constant one in all cases of kála-ázar,
and they are also met with, although in my experience not
quite to so marked a degree, in cases of anchylostomiasis,
being doubtless purely of a compensatory nature in each case.
It is in this way then that new red corpuscles are produced
in both diseases, but in the case of anchylostomiasis, there
soon becomes a dearth of hæmoglobin with which to stock
them. In kála-ázar, on the other hand, the hæmoglobin is not
lost to the economy, as it is in the former disease, for, when
the plasmodia destroy the red corpuscles, the colouring matter
becomes converted into pigment, and on the division of the
parasite into numerous small ones, and the breaking up of the
enclosing red corpuscle, such as occurs in the case of quoti-
dian fever every day at the time of the onset of the fever, this
pigment is set free in the blood, and gets filtered out by the
spleen, liver, and other organs, where it forms the pigmentary
deposits, which are of such a characteristic feature of chronic
malaria, and which will be shown in the next section, to be also
a marked and constant feature of kála-ázar. Thus, when in
this disease fresh red corpuscles are formed by the bone mar-
row, there is already a stock of iron in these organs in organic
combination, waiting to be used up to re-stock the red corpus-
cles, and this may even proceed until they contain more than
the normal amount, as shown by the frequent abnormally high
hæmoglobin value in kála-ázar. The ease with which the
hæmoglobin may be replaced constitutes the essential cause
of the difference of the type of the anæmia of kála-ázar from
that of anchylostomiasis, and thus we see every change which
I have found in the blood in either disease, is completely
accounted for by what we know of the causation and patho-
logy of them, and the complete differentiation of them as sepa-
rate and distinct diseases, which, however, sometimes compli-
cate each other, is placed on a firm basis.

      It is also evident from the above that while iron will be
essential in the treatment of the anæmia of anchylostomiasis,