ances which are responsible for a
state of edema in any other part of the body." The magnificent
experimental work of this investigator has shown that edema is nothing
more or less than an increased capacity of the protein colloid tissues
for water; that the most important factor leading to this increased
hydration capacity is an abnormal production or accumulation of acid
content, effected by those agencies which are instrumental in causing
sclerosis and an increase of blood pressure.

It seems that both of these theories afford an explanation for many of
the secondary pathological manifestations which characterize the
intra-ocular tissues during a glaucomatous onset.

Fischer criticizes the Henderson theory on the ground that increased
blood pressure alone does not lead to edema--edema is thwarted by high
blood pressure. On the other hand, if Fischer believes that sclerosis of
the meshwork of the iris angle is a result and not a cause of glaucoma,
then it would seem that Henderson has the better of the argument. The
physiological changes in this structure, which take place with advancing
age, can rightfully be looked upon as a predisposing factor in glaucoma.

Dr. Jackson has presented all other phases of this part of the
symposium in such a comprehensive manner that nothing further remains to
be said.

Pathology of Glaucoma

BY

JOHN E. WEEKS, M.D.,

New York City.

In reviewing the pathology of glaucoma it seems proper to consider the
various structures and tissues of the eye in logical order.

_Lids and Conjunctiva._ "The only change observed in these tissues is a
reflex edema, excited apparently by pressure on the ciliary nerves and,
probably, irritation of the vaso-motor fibers of the sympathetic."

_Lachrymal Gland._ Hyper secretion due to reflex irritation.

_Cornea._ As has been shown by Priestley Smith, the cornea in
glaucomatous eyes is, as a rule, smaller than in non-glaucomatous eyes,
the mean of a series of measurements being 11.1 mm. horizontally and
10.3 mm. vertically in glaucomatous and 11.6 mm. horizontally and 11
mm. vertically in non-glaucomatous eyes. In cases of considerable
increase of tension, particularly if the onset is sudden, the
circulation of lymph in the cornea is interfered with, the anterior
layers of the cornea become edematous, the spaces between the lamellae
filled with albuminous fluid. Some of this fluid finds its way through
Bowman's membrane, apparently by