Pathology and nature of kála-ázar.
109
The thoracic duct was also dissected out in all the earlier
cases, but was always found to be patent, so that the emacia-
tion was not due to any obstruction of this channel of absorp-
tion.
The cerebro-spinal
system.
A small quantity of fluid was often found beneath the
arachnoid, or in the ventricles of the brain,
which probably filled the vacancy formed
by slight atrophy of the organ. On sec-
tion the brain and spinal cord were normal. Pigmentation
was always found to be well marked on the under-surface of
the medulla oblongata, which in a few cases extending over
the pons as far even as the optic commissure, and over the
upper surface of the cerebellum. At first this was looked
on as constant and important sign of the disease, but it was
subsequently found that it was also to be met with under
the medulla in healthy persons, and even in anchylostomiasis,
so that it must be a normal condition in the natives of this
country, although I have not seen it mentioned in any book
on pathology. It extends down over the anterior sur-
face of the cervical portion of spinal cord. In one case
hæmorrhage beneath the arachnoid was the immediate cause
of death; but this was in a mixed case, and was, I think, due
rather to the blood changes brought about by the anchylos-
tomiasis factor than dependent on the fever of kála-ázar, as
I met with a similar hæmrnorrhage between the anterior surface
of the bladder and the peritoneum in a case of pure anchylos-
tomiasis.
The bone marrow.
It has recently been found in some cases of pernicious
anæmia observed in England, that the mar-
row of the shafts of the long bones, which
in health consists of yellow fat, is converted into red marrow,
such as is normally met with in the loose cancellous tissue of
the end of the long bones, and which forms the bulk of that
of the short bones. This red marrow has the function of form-
ing red corpuscles of the blood. An examination was there-
fore made of the marrow in the shaft of the femur or humerus