s so unequivocal, that it is a
matter of surprise that Askanazy chooses to deduce from it, the ready
transition from megaloblasts to normoblasts; whereas it is clear and
definite evidence that =megaloblasts are only produced under the
influence of a specific intoxication=. And in this way the presence of
megaloblasts in the pernicious anaemias is to be explained. The
megaloblastic degeneration of the bone-marrow depends on the presence of
certain injurious influences, of which unfortunately we are as yet
ignorant. Were it possible to remove them, it is quite certain _a
priori_ that the bone-marrow--if the disease were not too
advanced--would resume its normal normoblastic type of regeneration.
Clinical observation supports this contention in many cases. In
megaloblastic anaemias apparent cures are by no means rare, but sooner or
later a relapse occurs, and finally leads with certainty to a lethal
issue. These cases, familiar to every observer, prove with certainty
that the megaloblastic degeneration as such may pass away, and that in
isolated cases the conventional treatment by arsenic suffices to bring
about this result. A definite cure however under these conditions is not
yet attained, since we do not know the aetiological agent, still less can
we remove it. =For this reason, the prognosis of megaloblastic anaemia,
apart from the group of Bothriocephalus anaemia, is exceedingly bad.=

FOOTNOTES:

[8] Dunin, on the contrary, designates the appearance of nucleated red
blood corpuscles within the first 24 hours after the loss of blood as
normal and regular. This view does not correspond with the facts. A
single case on one occasion may exhibit a rarity of this kind.

[9] Probably the dot-like and granular enclosures in the red corpuscles,
which stain with methylene blue, and which Askanzy and A. Lazarus have
observed in numerous cases of pernicious anaemia are also products of a
similar nuclear destruction.

[10] It does not seem superfluous in this place expressly to emphasise,
that what has been said on the diagnostic importance of the megaloblasts
only holds for the blood of adults. For the conditions of the blood in
children, which vary in many respects from that of adults see "Die
Anaemie," Ehrlich and Lazarus, Pt. II. (Anaemia pseudoleukaemica infantum).

THE WHITE BLOOD CORPUSCLES.

The physiological importance of the _white blood corpuscles_ is so many
sided that they form the most interesting chap