774 



PHYSIOLOGY. 



ing tissue. By the chloride of gold method a picture is obtained of 

 this system of canals. The fourth layer: the posterior elastic layer, 

 or membrane of Descemet. This lamina is about 1 / 250 o of an inch 



Fig. 323. Section through the Human Cornea. (BouM and DAVIDOFF.) 



1, Anterior epithelium. 2, Basal cells. 



4, Substantia propria. 



Bowman's layer. 



thick, firm, refractive, and homogeneous in structure. When pieces 

 of this layer are separated, they curl up with the attached surface 

 innermost. At its circumference the lamina breaks up into bundles 



Fig 324. Corneal Corpuscles of Dog. (BoHM and DAVIDOFF.) 



of fibers, some of which form the pillars of the iris. To these 

 radiating and anastomosing bundles of elastic fibers prolonged from 

 the circumference of Desceinef.s membrane has been given the name 



