ZONULA CILIARIS 



545 



are fixed to its posterior surface close to its margin (post- 

 equatorial fibres). 



In that way the crystalline lens is firmly held in its place 

 in the fossa hyaloidea. Further, the degree of tension of its 

 suspensory ligament is influenced by the radiating fibres of 

 the ciliary muscle, which by their contraction pull upon the 

 ciliary processes, and produce relaxation of the zonula 

 ciliaris. 



Spatia Zonularia (O.T. Canal of Petit). In reality the 

 spatia zonularia constitute a more or less continuous circular 

 lymph space, which surrounds the circumference of the lens. 



Retina 



,Sclera 



-Perichorioidal space 



Ciliary muscle (radiating fibres) 



Ciliary muscle (circular fibres) 

 Sinus venosus sclerae 



Spatia anguli iridis 

 Ciliary process 

 Spatia zonularia 

 ""Suspensory ligament 



[ris 

 Cornea 



FIG, 231. Diagrammatic representation of the Ciliary Region, 

 as seen in vertical section. 



It lies between the anterior and posterior layers of the 

 suspensory ligament and is filled with a watery fluid. 



If the point of a fine blow-pipe is introduced into the spatia zonularis 

 through the suspensory ligament, the spatia can be partially, or, perhaps, 

 completely, inflated with air. Then the spatia present, collectively, the 

 appearance of a circular sacculatecl canal. 



Dissection. Remove the crystalline lens by snipping through 

 the suspensory ligament with scissors. 



Lens Crystallina. The crystalline lens is a biconvex, 

 solid, and transparent structure which lies between the iris 

 and the vitreous body, in the posterior wall of the posterior 

 and anterior chambers. It is enclosed within a glassy, elastic 

 capsule, to which the different parts of the zonula ciliaris 



VOL. in 35 



