THE EYE AND ITS APPENDAGES. 



together constitute a six-rayed star. In the adult lens, however, 

 the typical arrangement of the rays is greatly complicated by the 

 addition of secondary lines which obscure the figures. 



The capsule of the lens is a strong transparent elastic mem- 

 brane completely enclosing the lens and, at the periphery, intimately 

 uniting with the suspensory fibres of the zone of Zinn. The an- 

 terior capsule covering the front lens-surface is thicker (11-15 /-O 

 than the corresponding posterior capsule (5-7 //), the maximum 

 thickness being at the centre of the anterior lens-surface and the 

 minimum at its posterior pole. 



The zone of Zinn, zonula ciliaris, or suspensory ligament 

 of the lens, is the radially plicated, modified anterior continuation 

 of the hyaloid membrane of the vitreous body. At the ora ser- 

 rata the hyaloid becomes intimately united to the posterior surface 

 of the ciliary body as far as the ciliary processes, from whose sum- 



FIG. 385. 



Section through anterior segment of human eye, including cornea, sclera, iris, ciliary body, and 

 lens : a, b, substantia propria of cornea (C) and of sclera (S) ; c, sclero-corneal juncture ; d, conjunc- 

 tival tissue ; e, stroma of iris (/) ; f, connective tissue of ciliary processes (g) ; h, canal of Schlemm ; 

 k, trabeculae connecting sclera and ciliary body ; /, section of blood-vessel ; m, n, o, meridional, 

 radial, and circular fibres of ciliary muscle; />, continuation of hyaloid membrane into ligament (r) 

 of lens (L) ; s, spaces of Fontana ; t, muscular tissue of pupillary sphincter ; u, pigment-layer mark- 

 ing termination of retinal layers at pupil. 



mits thickened bands bridge across the intervening space and become 

 attached principally to the anterior surface and to the periphery of 

 the lens. Owing to the plication of the ciliary body over which the 



