The material on which this paper is based consisted of microscopic preparations from 300 eyes. Unless otherwise stated, the eyes were those of adults. In seventy of the slides the tissues were thought to have been present at birth, while in the remaining number they were considered the outcome of disease. According to their origin they are divided into the following groups :
1. CONGENITAL TISSUES
Remains of the Hyaloid Artery. These consist of: 1. Strands of varying length and thickness, of which there were eighteen examples. Fifteen came off from the nasal crest of the pit, in the horizontal meridian, and only three from the bottom of the pit. 2. Clumps of pure glial cells, representing a more advanced stage in the involution of the artery than the strands. There were seven, all situated on the nasal crest, in the horizontal meridian. 3. Membranes of pure glial cells, spread