THE EMBRYOLOGY OF THE EYE. 3 1 



lens and continue over its posterior surface. 

 No distinct anterior hyaloid or limiting mem- 

 brane of the vitreous can be found here. In 

 the space anterior to and outside the vitreous 

 we find zonula-fibres running from the ciliary 

 body to the lens. Farther back we find simi- 

 lar fibres, with nuclei lying on or in them, 

 running from one ciliary process to another or 

 from the smooth portion of the ciliary body to 

 a ciliary process, having their origin in and 

 beine inserted into the homogfeneous mem- 

 brane of the pars ciliaris. 



Whether the zonula-fibres originate from 

 the vitreous-fibrillae entirely, or in part from 

 cells of the vascular sheath of the lens is not 

 shown by my preparations, and the role of the 

 nuclei or cells which are found in the vitreous 

 at a late stage is uncertain in my mind. Until 

 very recently it was generally believed that 

 the zonula was derived from the vitreous. 

 Treacher Collins, however, in human em- 

 bryos, has observed spindle-cells of the lens- 

 sheath stretch out to form nucleated fibres 



