328 THE BLOODVESSELS OF THE EYE, BY TH. LEBER. 



brane, and there constitute the anterior branches of the vente 

 vorticosse. 



These parallel veins of the orbiculus ciliaris, between which, at great 

 distances from each other, the arteria3 recurrentes run, were formerly 

 considered to consist for the most part of arteries, and gave occasion 

 for the admission of the so-called anterior branches of the arterise 

 ciliares posteriores breves. 



A part only of the veins of the ciliary muscle unite to form 

 the small vense ciliares ant. (c), which perforate the sclerotic 

 near the margin of the cornea, and discharge themselves into 

 the veins of the recti muscles. 



These veins communicate with the venous vascular circle 

 (V), discovered by Schlemm, which is situated in the deepest 

 layers of the sclerotic, close to the corneal margin, and which is 

 usually termed the canalis Schlemmii, circulus or sinus venosus 

 cornese, and by me the plexus ciliaris venosus* This is 

 in reality by no means a simple canal, but a plexiform circle 

 of yeins/f" which nevertheless presents certain differences in 

 different eyes, and in different parts of the circumference of the 

 same eye. As a rule, -it appears in correspondence with the 

 ordinary description as a large (one-fourth of a millimeter wide), 

 flattened, and very thin- walled vein, but is almost always ac- 

 companied by one or more small veins, which branch off from 

 it, and after a short course again open into it. At many 

 points the larger vein splits up into two, three, or more 

 correspondingly fine branches, which anastomose, and gradually 

 reunite to form a large vessel. Very frequently the two 

 branches resulting from a division immediately reunite, so that 

 the course of a large vein is as it were interrupted by a small 

 island. Less frequently a large number (from five to seven) of 

 small, frequently anastomosing veins, either running close to 

 one another, or partially overlapping, occur, which then form a 

 delicate plexus, or may gradually again coalesce to form a large 

 vessel. 



* Loc. cit., p. 19. For illustrations see Taf. iii. and the Archiv fur 

 Ophthalmologie, Band xi., Heft, i., Taf. ii., fig 2. 



+ Rouget, Comptes rendus et Memoires de la Societe de Biologie, 1856, 

 p. 118. 



