This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1916 edition. Excerpt: ... C, Cornea; Scl, Sclerotic; Ch, Choroid; R, Retina; or, Ora Serrata; Z. Zonule of Zinn or Suspensory Ligaments; ii, Petit's Canal; p. Edge of Pupil; P, the most prominent part of the Ciliary Process; sp, Sphincter Pupillse Muscle; s. Canal of Schlemm; L, Conjunctiva; B, Lens; t, Angle of Filtration as they approach the front of the eye. The retina is attached in two places, at the optic disc and at its anterior border, the ora serrata. It is not attached to the choroid, but simply lies on it. In examining the retina with the ophthalmoscope you will notice the optic disc on the nasal side, which marks the entrance of the optic nerve into the globe. The macula hitea, which is the most sensitive spot of the retina (sometimes called the yellow spot, as it is said to turn yellow after death), is situated slightly on the temple side. The function of the retina is to receive the impressions of the waves of light and transmit them through the optic nerve to the brain. The space between the iris and cornea is known as the anterior chamber of the eye, and that between the iris and the lens, as the posterior chamber. Both of these chambers are filled with a transparent, watery fluid known as the aqueous humor. The large chamber back of the crystalline lens is known as the vitreous chamber, and contains the vitreous humor, which occupies a little more than three-fourths of the eyeball. It is a perfectly transparent substance, about the consistency of the white of an egg, and is enclosed in a thin transparent sac known as the hyaloid membrane. This membrane divides at the ciliary body and forms what is known as the anterior and posterior suspensory ligaments, which are attached to the lens capsule, thus forming what is known as Petit's Canal and the...