THE EYE. 



POST.ETHM. 



-SUP.EXT.MUSC. 





O MENINGEAL. 



branches from the Meibo- 

 mian glands and from the 

 orbicularis and integument, 

 below which it forms a 

 tortuous venous plexus, with 

 large and irregular meshes. 



Fig. 6. SECTION OF THE UPPER 



EYELID, WITH THE ARTERIES 



INJECTED. (Modified from 

 Merkel.) 



The course of the nervous twigs 

 is also shown. 



The blood from this plexus 

 passes externally into the 

 superficial tsmporal and in- 

 ternally into the facial vein. 



Lymphatics. There are 

 two networks of lymphatic 

 vessels in each eyelid, one 

 in front of, the other behind 

 the tarsus. The former re- 

 ceives lymph from the in- 

 tegumental and muscular 

 structures of the lid, the 

 latter from the Meibomian 

 glands and conjunctiva. The 

 networks are connected by 

 vessels which pierce the tarsi, 

 but less freely in the lower 

 than in the upper eyelid. 

 The efferent lymphatics find 

 their way mesially along the 



in the lower lid. The two arches in the 

 upper lid are joined here and there by small 

 anastomotic arteries. Branches pass in 

 each lid from the tarsal arches, 1, for- 



Fig. 5. PLAN OF THE OPHTHALMIC ARTERY, SHOW- 

 ING THE TYPICAL MODE OF ORIGIN OF ITS 



BRANCHES. (G. D. T. after Meyer. ) 



wards to supply the orbicularis muscle, and 

 the integumental structures ; 2, backwards 

 into the tarsus to supply the Meibomian 

 glands ; and 3, backwards around the upper 

 and lower edges of the tarsus to supply the 

 conjunctiva palpebrarum. The veins of 

 the eyelids are disposed in two series or 

 networks. The one, post-iarsal, receives 

 branches from the conjunctiva and a few 

 from the Meibomian glands ; its blood 

 passes for the most part into the ophthal- 

 mic vein. The other, or pre-tarsal, receives 



-^ Muscle of ~RLolasi, 



QlounoL of Moll 



