and Rieder. Were the hypothesis true,
transitional stages ought to be found with ease in every sample of
normal blood. Rieder and Mueller themselves are unable to bring forward
any positive result of this kind, else they would hardly have been
contented to fall back on the authority of Max Schultze, who professed
to shew the transitional forms between the finely and coarsely granular
leucocytes in the circulating blood. The authority of Max Schultze in
morphological questions stands high, and very rightly; but one ought not
to rely upon it for support in problems that are really histo-chemical,
and which should be solved by their appropriate methods.

As a logical consequence of their view, and in decided opposition to
Ehrlich, Mueller and Rieder assume that the eosinophil cells of the
bone-marrow "are far rather the expression of a storage than of a fresh
formation there. =The bone-marrow therefore should be regarded in
reference to the coarsely granular cells of the blood more as a storage
depot, where these cells serve other purposes, which for the present
cannot be more closely defined.="

The chief reason for this assumption, these authors see in the fact,
that the majority of the eosinophils in the bone-marrow are mononuclear,
whilst those of normal blood possess a polymorphous nucleus. Mueller and
Rieder should themselves have raised the obvious objection that the same
holds good for the nucleus of the neutrophils. They would then have seen
the fault in their theory; for according to it the most important blood
preparing organ constitutes as it were, not the cradle of the blood
cells, but their grave. The simplest and readiest explanation, based
too upon histological observation, is surely this: that the mononuclear
eosinophil cells grow into polynuclear in the bone-marrow, but that the
latter only reach the blood by means of their power of emigration. As
this view has been accepted by the great majority of authors since
Ehrlich's paper "On severe anaemic conditions," we believe we may content
ourselves with the above objections to the Mueller-Rieder theory,
although it has even quite recently found supporters (_e.g._ B.
Lenhartz). H. F. Mueller moreover in his paper on bronchial asthma (1893)
takes a position different from his earlier, and approaching that of
Ehrlich.

In considering the production of polynuclear eosinophilia we may best
start from an experiment of E. Neusser's. Neusser found in a pemphigus