380 



ANATOMY IX A NUTSHELL. 



ture of the sclerotic. It is continuous with the sclerotic coat. The posterior 

 surface o( the cornea is concave and projects a little farther backward than the 

 anterior convex surface. The posterior surface of the cornea forms the anterior 

 boundary of the anterior chamber which contains aqueous humor. Its anterior 

 surface is covered with conjunctiva which, in this position, constitutes one of 

 the epithelial layers. It is of a uniform thickness and is more curved in youth 

 than in old age, when it becomes flattened. 



The ligamentum pectinatum iridis or the pillars of the iris, are formed by 

 fibers from the stroma of the cornea which pass backward and outward to the 

 iris. They form an annular meshwork encircling a series of lymphatic spaces 



PLATE CXCVIII. 



,- FROM RAMUS COMMUNICANS 

 | TO VERTEBRAE AND INTERCOSTAL 

 AND LUMBAR VESSELS 



TO HIGHER GANGLION 

 0.', 



SOMATIC VASOMOTOR, PILOMOTOR, SECRETORY 

 H 



SYMPATHETIC TRUNK 



MEDULLATED FIBERS PASSING 



a THROUGH THE GANGLION TO 



PREVERTEBRAL PLEXUS OR 



DIRECTLY TO VISCERA 



* GRAY VISCERAL FIBERS 



RAMI EFFERENTES 



SYMPATHETIC TRUNK 



vertebrae 



ligaments 

 spinal vessels 

 and Dura 



NTRAL SPINAL NERVE ROOT 



DORSAL SPINAL NERVE ROOT 



ACCOMPANYING DORSAL ROOT TO DURA 



Showing the Rami Communicantes. 



(spaces of Fontana) which communicate with the anterior chamber, and the 

 canal of Schlemn, and the scleral veins. 



Structure. — The cornea consists of four layers, viz: (1) Several strata 

 of epithelial cells continuous with those of the conjunctiva, (a) The external 

 set consists of columnar epithelium, (b) Two or three layers of polyhedral 

 cells, (c) Three or tour layers of scaly epithelial with flattened nuclei. (2) A 

 (hick, central, fibrous structure called the substance propria. It is fibrous, 

 tough, unyielding, perfectly transparent and continuous with the sclerotic and 

 consists of aliout sixty flattened lamellae, the fibres passing one lamella to an- 

 other. The corneal spaces are between the hunelhe, which are connected by an 



