THE EYE. 



261 



plicated arrangement of the blood vessels of the eyeball. 

 We must leave this to more special works. 



We would add, however, a few words concerning the 

 lymphatics of. the eyeball 

 (Fig. 208), basing them on 

 Schwalbe's admirable work. 



We may assume with this 

 investigator an anterior and 

 a posterior system of lym- 

 phatics. 



The former, arising from 

 the iris and ciliary processes, 

 has its central reservoir in 

 the anterior chamber of the 

 eye. To this division be- 

 long also the lymphatics 

 of the cornea and conjunc- 

 tiva. 



All that lies behind the 

 ciliary processes forms the 

 posterior lymphatic system. 

 The sclerotic and the cho- 

 roid are perhaps without 

 definite lymphatic canals. 



The cup-like space between both membranes, with which 

 we are already familiar as the lamina fusca, has, on the 

 contrary, the signification of a lymph reservoir. This is 

 Schwalbe's perichoroideal space (p). From it (at the eleva- 

 tion of m r of our figure) occurs the transition of the lym- 

 phatic fluid into the so-called Tenon's space (/), that is the 

 interval between the outer surface of the sclera and the Te- 

 non's capsule of the eyeball. The connecting lymph canals 

 surround the vasa vorticosa of the choroid in a sheath-like 

 manner. Posteriorly the Tenon's reservoir continues into 

 the supravaginal space (s p v), a cylindrical sheath membrane 

 of the optic nerve.- 



Key and Retzius, the two able investigators mentioned in 



Fig. 208. — The posterior lymphatics of the hog's 

 eye : c, conjunctiva ; m r, the recti muscles : 

 111 retr., retractor bulbi ; a, layer of fat: 7>, the 

 outer sheath of the optic nerve ; t, the '"Tenon's" 

 space, passing backwards into the "supravaginal," 

 s />7' : .? 6 v, " subvaginal " space between the in- 

 ner and outer sheath of the optic nerve ; /. "per- 

 ichoroideal" space connected with the Tenon's 

 space by oblique passages. 



