XXXII.] 



THE EYE. 



359 



layers of transparent fibrous tissue arranged in laminae. The 

 laminae, while arranged in the main parallel to each other, have 

 connecting processes joining adjacent laminae. Between the laminae 

 oval spaces, and in each space a nucleated cornea corpuscle (fig. 

 333> <"), which, as seen on edge, is thin and flattened. The processes 

 of these corpuscles are best seen in gold specimens. 



(fl. ) The posterior elastic lamina, or membrane of Descemet, 

 a well-marked, thin, transparent, hyaline lamina, with sharply 

 defined outlines, and covered posteriorly by 



(e.) The posterior epithelium, consisting of a single layer of 

 large flattened nucleated cells, seen in profile. They are apt to be 

 displaced if the section be roughly handled. 



If the posterior elastic lamina be broken across, it is apt to curl 

 up. It stains readily with carmine. 



FlQ. 333. V.S. Cornea, a. Epi- 

 thelium ; h. Anterior elastic 

 lamina; c. Cornea! corpuscles; 

 I. Lamclhc of cornea ; ft-rf, 

 Siilistantia propria; d. Des- 

 cemet's membrane; and e. Its 

 epithelium. 



FIG. 



1*10. 334 Corneal Corpuscles, and a few 

 Nerve-Fibrils of Frog. Gold chloride. 



2. Nerves of the Frog's Cornea. In a pithed frog, squeeze the 

 head to make the eyeball project, and with a sharp razor cut off the 

 cornea. Wash it in normal saline, treat it with gold chloride by 

 the lemon-juice method (p. 79). 



After impregnation with the gold solution, with scissors make 

 three snips into its margin, dividing it into three sections, so that 

 it may He flat on a slide. Mount in Farrant's solution. 



(a.) (L and H) Observe the branching cornea corpuscles, 

 arranged in many layers, one under the other, readily seen by 

 raising or depressing the lens (fig. 334). The numerous processes 

 given off from ,the cells anastomose with similar processes from 



