1032 



ORGANS OF SPECIAL SENSE 



nerve than the short ciliaries, run horizontally forwards between the sclerotic and 

 chorioid, one on each side of the globe. On arriving at the ciliary body, they join 

 with the anterior ciliary arteries, forming the circulus arteriosus major, which 

 sends off branches to the ciliary processes and the iris. The long ciliaries also 

 give twigs to the ciliary muscle, and small recurrent branches run backwards to 

 anastomose with the short ciliary arteries. The arteries of the iris run radially to- 

 wards the pupillary border, anastomosing with one another opposite the outer border 

 of the sphincter so as to form the circulus arteriosus minor. 



(3) The anterior ciliary arteries come from the arteries of the four recti mus- 

 cles, one or two from each; they run forwards, branching as they go, and finally 

 pierce the sclerotic near the corneal border. Outside the globe they send twigs 

 to the adjoining sclerotic, to the conjunctiva, and to the border of the cornea. 

 After passing through the sclerotic the arteries enter the ciliary muscle, where they 

 end in twigs to the muscle and to the circulus arteriosus major, and in recurrent 

 branches to the chorioid. 



FIG. 731. THE LYMPHATIC SPACES OP THE EYEBALL. (Diagrammatic. After Fuchs.) 



Anterior ciliary rein 

 CANAL OF SCHLEMM 



( PROLONGATION OF TENON'S 

 " CAPSULE ON TENDONS 



PERICHOR10IDAL SPACE 

 HYALOID CANAL 



SPACE AROUND VENA VORTICOSA 

 COMMUNICATING WITH THE 

 PERICHORIOIDAL SPACE AND 

 TENON'S SPACE 



TENON'S SPACE 



SUPRAVAGINAL SPACE 



INTERVAGINAL SPACE 



Veins. The venous blood from almost the whole uveal tract (chorioid, ciliary 

 processes and iris, and part of the ciliary muscle) ultimately leaves the eyeball by 

 (1) the venae vorticosae, which have been already noticed in describing an antero- 

 posterior section through the globe (p. 1025). One large vein passes backwards from 

 each vortex, piercing the sclerotic obliquely; it is joined by small episcleral veins 

 when outside the globe. 



(2) The anterior ciliary veins commence by the junction of a few small veins 

 of the ciliary muscle; they pass outwards through the sclerotic near the corneal 

 border, receiving blood from the veins in connection with Schlemm's canal, and 

 afterwards from episcleral and conjunctival veins, and from the marginal corneal 

 plexus. Finally they join the veins running in the recti muscles. 



Lymphatic system of the eyeball. Apart from those in the conjunctiva 

 there are no lymphatic vessels in the eyeball, but the fluid is contained in spaces of 

 various sizes. These are usually divided into an anterior and a posterior set. 



1. Anteriorly, we have the anterior and posterior aqueous chambers, which 

 communicate freely through the pupil. The aqueous humour is formed in the 



