722 



THE EYE. 



ophthalmic artery pierce the sclerotic close to the optic nerve, and divide 

 into branches which pass forward in meridional directions in the choroid 

 membrane. Communicating freely they diminish in size, and entering the 

 choroid form a close network of fine capillaries (tunica Euyschiana) already 

 described. 



Fig. 467. 



Fig. 468. 



Fig. 467. LATERAL VIEW OP 

 THE ARTERIES OF THE CHO- 

 ROID AND IRIS (from Ar- 

 nold), f 



a, optic nerve ; &, part of 

 the sclerotic left behind, the 

 greater part and the cornea 

 having been removed ante- 

 riorly ; c, ciliary muscle ; d, 

 iris ; 1, posterior ciliary ar- 

 teries piercing the sclerotic and 

 passing along the choroid ; 2, 

 one of the long posterior 

 ciliary arteries ; 3, several of 

 the short or anterior ciliary 

 arteries. 



The veins of the choroid 

 coat constitute an outer 

 layer, partially separable 

 from the arterial network, 

 and easily recognised by 

 the direction of the larger 

 vessels. These converge 

 to four nearly equidistant 

 trunks, which pass through 

 the sclerotic about half 

 way between the margin 



Fig. 468. LATERAL VIEW OF 



THE VEINS OF THE CHOROID 



(from Arnold). 



The preparation is similar to 

 that represented in the pre- 

 vious figure. 1, 1, two trunks 

 of the vense vorticosse at the 

 place where they leave the 

 choroid and pierce the sclerotic 

 coat. 



of the cornea and the entrance of the optic nerve, and pour their contents 

 into the ophthalmic vein. From their whorl-like arrangement they are 

 known as the vasa vorticosa. 



The blood-vessels of the ciliary processes are very numerous, and are derived 

 from the anterior ciliary, and from those of the fore part of the choroidal 

 membrane. Several small arterial branches enter the outer part of each ciliary 

 process, at first running parallel to each other and communicating sparingly. 

 As they enter the prominent folded portion, the vessels become tortuous, sub- 

 divide minutely, and inosculate frequently by cross branches. Finally they 

 form short arches or loops, and turn backwards to pour their contents into 

 the radicles of the veins. 



On the free border of the fold, one artery, larger than the rest, extends 



