the latter than in the normal state. This
circumstance in itself is apt to cause capillary engorgement. In the
finest capillaries permitting only a string of corpuscles, one behind
the other but none abreast, to pass through in the normal state,
dilatation may cause blockage by two or three becoming wedged in abreast
and closing the lumen of the vessel by a sort of embolism. On the
arterial side of this obstruction the crowded corpuscles force their way
through the porous cement substance by what little "vis a tergo" there
may be left yet, whilst in the venous side, in the small veins
corresponding with the closed capillaries, engorgement must necessarily
take place through this "vis a tergo" being entirely absent, and
diapedesis, which here also has been observed, follow in due course. The
writer has always been inclined to take this view, the correctness of
which appears to be borne out by an experiment recorded by Feoktistow.
He found on sprinkling a two per cent. solution of snake-poison over the
mesentery of an healthy animal, that wherever a drop of the solution
fell, almost immediately the capillaries and small veins became dilated
and small point-like effusions of blood appeared, gradually enlarging
and ultimately becoming confluent with adjoining ones. Large haemorrhagic
surfaces were thus formed in a comparatively short time. Here paralysis
of the nerve-cells interspersed in the vaso-motor nerve-ends was
evidently the first effect, followed by dilatation of the capillaries
and immediately afterwards by effusion. Without some obstruction within
the capillaries, like that above described, effusion in this purely
local poisoning process appears unexplainable.

The special preference which the viper-poison has for the vaso-motor
sphere will hereafter be referred to. Haemorrhages from Australian
snake-poison are comparatively rare. Even at the bitten place there is
as a rule very little swelling and effusion and frequently none at all.
When it occurs it quickly disappears after strychnine injections. Only
a few cases have been reported as yet of blood-vomiting. In one of these
the haemorrhage took place soon after the bite and was so considerable
that it must have arisen from actual rupture of vessels consequent on
abdominal engorgement and not from mere diapedesis. It is very doubtful
whether the latter ever takes place here as it does after viper-bite in
India and elsewhere. Even the death-adder, although half a v