294 



THE NERVOUS SYSTEM 



The lens, being enclosed in an elastic capsule, always tends 

 to assume a spherical form, but is prevented from doing so 

 by the tension of the suspensory ligaments (due to the intra- 

 ocular pressure), which attach it to the cihary processes. The 



imus venosus 



,cniuni 



Corpus Zonula 

 ciliare cillaris 



Retina 



Fig. 49. — Anterior part of eyeball showing relation of iris, lens, ciliary 

 bodies and corneosclerotic junction (from Starling's Principles of 

 Physiology). 



cihary muscle consists of two parts : circular fibres which 

 run round the eye at the corneosclerotic angle, and meri- 

 dional fibres which pass backwards to be inserted into 

 the cihary processes. When this muscle contracts the 

 circular fibres draw the cihary processes as a whole into 



