196 Dr Knox on the Limits of the Retina 



wished, but it seemed to me, that, again assuming the form of 

 excessively delicate fibres, and laying aside that of a membrane, 

 it penetrated the ciliary processes just described, and thus dis- 

 appeared. This, however, I consider as merely a conjecture, 

 for, notwithstanding the use of the strongest glasses, I could 

 not satisfy myself as to its correctness. In order to have a 

 perfect view of the exact formation of the ciliary body or fi- 

 bres, the inner membrane, which it receives from the retina, 

 and which accompanies it quite to the crystalline humour, must 

 be removed as much as possible.* We then see a range of 

 parallel and straight fibres arising from the sclei'otic, and pro- 

 ceeding forward towards the crystalline ; they are remarkably 

 strong, and do not require any glass to distinguish them. When 

 they have proceeded for several lines, they unite with another 

 set of fibres which arise also from the sclerotic, but nearer the 

 pupil. These fibres join the ones first described obliquely. 

 Both sets unite to form a firm homogeneous mass, in which no 

 fibres can be discerned, and from this arises the central layer 

 of fibres which complete the circle, and proceed to the crys- 

 talline itself, to which they are firmly united. From the inner 

 margin of these fibres an excessively delicate membrane seems 

 to be transmitted quite across, and to be thus interposed between 

 the anterior and posterior hemispheres of the lens; but the fibres 

 run into, and are, as it were, continuous with the outer layers 

 of the lens, whose structure seems to differ somewhat from the 

 more internal or central portion. From the point where the 

 two sets of fibres meet but externally, arises another circular 

 iris-shaped bodv, which, in like manner with the posterior 

 one, passes in between the hemispheres of the lens, contribut- 

 ing to fix this humour the more firmly; and it even seemed to 

 me, in one of the specimens examined, that this anterior layer 

 of fibres was very intimately united by fibrous matter sent to 

 it from the surface of the anterior hemisphere of the lens. 

 However this may be, it is evident that these two layers of fi- 

 bres are distinct, and that the anterior, as we should expect, 

 is most intimately connected with the anterior hemisphere of 

 the lens. When we remove this portion of the lens, we find 



" This I have found to be quite impracticable in the smaller species of 

 Sepiae. 



