22 



INNER VATION. 



CHAP. xvn. 



styled the vasa vorticosa (fig. 112, e, e). The arteries run between 

 these, but less regularly. 



Fig. 112. Fig. 113. 



Choroid and Iris, exposed by turning aside the sclero- 

 tica: c, c. Ciliary nerves branching in the iris. d. Smaller 

 ciliary nerve, e, e. Vasa vorticosa. A. Ciliary ligament 

 and muscle, k. Converging fibres of the greater circle of 

 the iris. I. Looped and knotted form of these near the 

 pupil, with the converging fibres of the lesser circle of the 

 iris within them. o. The optic nerve. From Zinu. 



Vessels of tha Choroid, Ciliary 

 processes and Iris, inner surface. 

 a. Portion of the capillary 

 network or tunica Ruyschiana. 

 b. Ciliary processes, c. Portion of 

 the iris. From an Infant. Mag- 

 nified 14 diam. After Arnold. 



Fig. 114. 



The capillary network of the inner surface is so close that there is 

 no room for pigment-cells in its interstices; but between it and the ar- 

 teries and veins, as well as among the veins themselves, there is a great 



abundance of colouring matter, 

 which deeply tinges the whole 

 thickness of the membrane. 



The pigment-cells in the sub- 

 stance of the choroid (fig. 114, 

 B) are extremely irregular in 

 shape, and lie in various direc- 

 tions amongst the other ele- 

 mentary tissues. Similar ones 

 are found in the iris, and 

 sparingly in the anterior part 



A. Choroidal Epithelium, with the cells filled with /? ,- n , rm, 



pigment, except at a, where the nuclei are visible. OI the SClerOtlC. Iney are SO 



*- Grains 



loaded with pigment that their 



B. Pigment-cells from the substance of the Choroid. i r>, i T i > 



A dctac-hcd nucleus is seen. Magnified 320 diameter*. nuclei ai'C OltCll ODSCUred by it. 



