to
Charcot-Leyden's crystals, eosinophil cells only. One must therefore
assume that within the bronchial tree there exists material which
attracts the eosinophils. This supposition is also supported by the
close connection that obtains, according to many observations, between
the severity of the disease and the eosinophilia. Thus v. Noorden
records that the eosinophil cells are more numerous about the time of an
attack. They accumulated in especially large numbers after attacks had
rapidly occurred several days in succession. =That the increase of the
eosinophil cells in this instance is directly connected with the
attacks, and is not the expression of a permanent constitutional
anomaly=, is shewn by a case in which v. Noorden found 25% eosinophils
during the attack, and a few days later could only observe one example
in twelve cover-slip preparations: a diminution therefore of this group
of cells.

The observations of Canon in skin-diseases are quite similar, for he
shewed that the extension of the disease determines the degree of
eosinophilia more than its intensity. And it is the former factor which
directly determines the quantities of the specific agent that pass into
the blood.

To the Mueller-Rieder hypothesis, and the chemiotactic theory of
eosinophil leucocytosis a third has lately been added, which may be
shortly called =the hypothesis of the local origin= of the eosinophil
cells. A. Schmidt has, with special reference to asthma, raised the
question "whether in the extensive production of eosinophil cells in
asthma, local production in the air passages is not more probable than
origin from the blood. One may well regard the increase of the
eosinophil cells in the blood of an asthmatic as secondary." This view,
which has also been advocated by other authors, rests more particularly
on the following facts and considerations:

1. That in various diseases of the nose, especially in mucous polypi
and hyperplasia of the mucous membrane (Leyden, Benno Lewy and others),
a great accumulation of eosinophil cells is found in these tissues,
whilst they are apparently not increased in the blood. This objection is
easily laid aside from the chemiotactic point of view. For if in the
places in question substances are present which act chemiotactically on
the eosinophil leucocytes, in the course of time marked accumulation
must occur, without an increase of their number in the blood. One might
as well conclude from Neuman