THE EYE. 753 



with from nine to sixteen rays of various lengths, and rarely quite 

 uniform, among which, however, three principal rays may be distin- 

 guished. The course of the fibres is consequently rendered more com- 

 plex, and the rather so, because fibres attached to the sides of the rays 

 converge in an arched manner, so that the latter appear, as it were, 

 feathered, or form whirls (vortices lentis); but, notwithstanding this, 

 the course of the fibres remains essentially the same in all respects as 

 that above described, inasmuch as in this case also the anterior and 

 posterior "stars" do not correspond with each other, and no fibre 



Fig. 307. 



extends from the one pole to the other. In the " stars," the substance 

 of the lens is not formed of tubes as elsewhere, but is in part finely 

 granular, in part homogeneous ; and, consequently, since the " stars" 

 involve all the layers, three or more, vertical, non-fibrous lamella 

 (" central planes," Bowman) exist in each half of the lens. Moreover, 

 the tubes themselves in the neighborhood of the " stars" become less 

 distinct, are gradually fused together, and ultimately lost, without any 

 line of demarcation, in the substance in question. 



229. The vitreous body or humor, occupies the entire space between 

 the lens and the retina ; its relations being such that excepting at the 

 point of entrance of the optic nerve, where the connection is rather more 

 intimate, it is only in loose apposition with the retina, whilst it is very 

 closely united with the corona ciliaris and the lens itself. The mem- 

 brane enclosing the vitreous body, or the hyaloid membrane, which 

 behind the ora serrata constitutes an extremely fine and delicate, per- 

 fectly transparent membrane scarcely perceptible under the microscope, 

 in front of that part becomes rather firmer (Fig. 296 t), and is continued 

 to the border of the lens as the pars ciliaris hyaloidece s. zonula Zinnii 

 (" suspensory ligament of the lens," Bowman [and Ketzius]), where it 



FiG. 307. Lens of the adult, after Arnold, to show the '-star." 1, anterior aspect ; 2, 

 posterior. 



48 



