164 EQUINE ANATOMY. 



At the point of entrance of the optic nerve, there is an oval 

 point I inch in diameter, where all nerve elements are absent ; 

 this is the Wind spot. 



Fig. 26. 



THEORETICAL SECTION OF THE HORSE S EYE. 



a, Optic nerve; i, Sclerotic; c, Choroid; d, Retina; e, Cornea; y, Iris; £-, It, Ciliary circle 

 (or ligament) and processes given off by the choroid, though represented as isolated from 

 it, in order to indicate their limits more clearly; /, Insertion of the ciliary processes on 

 the cr3 stalline lens; j, Crystalline lens; k. Crystalline capsule; /, Vitreous body; ;«, «, 

 Anterior and posterior chambers; o, Theoretical indication of the membrane of the 

 aqueous humor; /,/, Tarsi; q, q. Fibrous membrane of the eyelids; r, Elevator muscle 

 of the upper eyelid; s, s, Orbiculaiis muscle of the eyelids; t, t, Skin of the eyelids; tc, 

 Conjunctiva; zi, Epidermic layer of this membrane covering the cornea; x, Posterior 

 rectus muscle; y, Superior rectus muscle; z, Inferior rectus muscle; w, Fibrous sheath 

 of the orbit (or orbital membrane) . 



Humors. 



These are the aqueous and vitreous humors, and crystalline 

 humors. 

 The Aqueous humor fills up the space lying between the 



