1030 



ORGANS OF SPECIAL SENSE 



have been described in it, but these are really artificial products. In certain situa- 

 tions spaces exist in the vitreous mass, the most determinate of which runs in the 

 form of a canal from the optic papilla to the posterior pole of the lens, corresponding 

 to the position of the foetal hyaloid artery (hyaloid canal, or canal of Cloquet). 

 Other very fine spaces are described running circularly in the peripheral part of 

 the vitreous concentric with its outer surface. Microscopically, wandering cells 

 are found in the vitreous, which often here assume peculiar forms which the 

 observer can, not infrequently, study subjectively. 



The aqueous humour is a clear, watery fluid, occupying the space between 

 the cornea on the one hand, and the ciliary body, suspensory ligament, and lens on 



FIG. 729. DIAGRAMMATIC REPRESENTATION OF THE BLOOD-VESSELS OF THE EYEBALL. 



(Leber.) 



Arteries red; veins blue. 



Canal of Rchlemm and con- 

 nections with anterior 

 ciliary vein 



Branch from ciliary body to 

 anterior ciliary vein 



Vessels of ciliary processes 



Vein from iris and ciliary 

 body to vena vorlicosa 



Branch from short posterior 

 ciliary artery to optic nerve 



Short posterior ciliary artery 



Vena centralis retinas 



Marginal corneal pf exits 



__ Anterior conjuttclintl rein 



'imihis iridis major 

 Posterior coujuin:liral rein 



P<tx/i'/-i<ir coiijniir/ii'n! nrfi'ri/ 

 Anterior ciliary artery 



Epvtcleral rein 

 Episcleral artery 



Vena vorticosa 



Posterior lung ciliary artery 

 Posterior short ciliary arteries 



Vessels (if ji/nf sheath of optic nerve 

 ] T eSt'ls of dnral sheath 



A f/eri-i O'litralts retince 



the other. The iris, projecting into this space, has both its surfaces bathed in the 

 aqueous; but, as its inner part rests on the lens, it is regarded as dividing the space 

 into two parts, an anterior larger, and a posterior smaller, aqueous chamber, 

 which communicate freely through the pupil. 



Ciliary nerves of the eyeball. The long and short ciliary nerves, after per- 

 forating the sclerotic, run forwards between it and the chorioid to the ciliary region, 

 where they form a plexus, from which proceed branches for the ciliary muscle, the 

 iris, and the cornea. The nerves of the iris enter it at its ciliary border, and run 

 towards its pupillary edge, losing their medullary sheath sooner or later, and sup- 



