THE EYE. 245 



THE LENS. 



The lens is a transparent double convex body, 

 of sufficient firmness to maintain its form when 

 removed from the eye, and is enclosed in a homo- 

 geneous elastic capsule which is thicker on the 

 anterior than on the posterior surface. To the peri- 

 pheral zone of the capsule, on both anterior and 

 posterior surfaces, the suspensory ligament is firmly 

 attached. The body of the lens, although perfectly 

 transparent, is by no means structureless. Behind 

 the anterior wall of the capsule lies a single layer of 

 flattened polygonal cells, which at the equator 

 gradually lengthen out to form very much elongated, 

 band-like nucleated cells, or lens-fibres, which run- 

 ning meridionally, and joined by inter-fibrillar ce- 

 ment substance make up the greater part of the 

 body of the lens. The lens-fibres are slightly ridged 

 upon the surface, and have, on transverse section, a 

 flattened hexagonal form ; they are so intimately 

 joined to one another at their sides by the cement- 

 substance, that under certain circumstances they 

 may be peeled off in layers. 



The course of the fibres in the lens is somewhat 

 complicated, but it may be said in general that they 

 run meridionally from one-half of the lens, in broad 

 sweeps, over into the other ; inasmuch, however, as 

 the individual fibres are not long enough to reach 

 the entire distance from one end of the pole around 

 to the other, they commence along certain definite 



