) in buphthalmos. Seefelder (Graefe's Arch. V. LXIII.
1906) mentions the abnormal position and abnormal narrowing of Schlemm's
canal and the imperfect and insufficient differentiation of the
cornea-scleral junction. In all of the cases in which the eye has been
examined microscopically obliteration of Schlemm's canal has been
reported. This is thought to be a defect in development. Magitot (Ann.
d'Oculis CXLVII) suggests that injury to mesoderm which pushes itself
between the ectoderm and anterior surface of the lens would account for
the failure in development of Schlemm's canal. The changes that occur in
the tissues of the eye appear to be largely due to the stretching
consequent on the more or less uniform distentions of the globe as a
result of hypertension.

_Cornea._ This portion of the fibrous membrane is enlarged, globous or
flattened, irregularly thinned, particularly at the periphery, where it
may be as thin as tissue paper, nebulous because of the stretching of
its fibers principally, but in some degree (differing in different
cases) to edema of the epithelial layer. Fissures occur in Descemet's
membrane.

_Anterior Chamber._ This is very deep in the greater number of cases.
However, this rule has many exceptions.

The vascular tunic may be congested in young infants, but atrophy soon
develops and may reach an extreme degree. The sclera ordinarily becomes
quite thin throughout, but may retain almost a normal thickness at the
equator of the globe and posteriorly. Posterior sclera ectasae may
develop. The iris, as a rule, hangs free from the cornea, often
tremulous because of retraction of the lens beyond the iris plane. In
some cases the iris is partly or totally adherent to the posterior
surface of the cornea.

The vascular membrane (iris, ciliary body and chorioid) and the retina
become atrophic, the atrophy varying in degree in various parts.
Detachment of the retina may occur, often preceded by or accompanied by
subretinal hemorrhage. The optic disc becomes deeply cupped and the
tissues of the optic disc and optic nerve extremely atrophied. The
crystalline lens may become cataractous and shrunken. Spontaneous
rupture of the suspensory ligament with consequent subluxation of the
lens may follow.

_Secondary Glaucoma._ The pathological conditions that precede
secondary glaucoma are many and differ widely. They may be briefly
classified as:

1. Those that cause a partial or complete closure of the lym