SENSE OF SIGHT. 199 



like the folds of a ruffle, of which there are about 70 in the 

 human eye, all arranged in a radiated manner round the lens, 

 as represented in the following cut. 



Fig. 5. 



Section of the eye magnified, showing the ciliary processes, the pig- 

 mentum nigrum, the retina, and the choroid coat. 



16. The ciliary processes are thus cellular and vascular, 

 and some have thought muscular, in order to give support to 

 the weight of the crystalline and vitreous bodies, to keep 

 them from falling towards the iris, or into the aqueous hu- 

 mour. To accomplish this, we find them placed immme- 

 diately in front of the vitreous humour, and closely embrac- 

 ing the circumference of the crystalline lens, and then to 

 strengthen the slender materials of which it is formed, we 

 find it implanted in little furrows on the surface of the vit- 

 reous body, glued as it were to it, and adhering to it very 

 firmly. We know that very substantial fabrics are made by 

 plaiting and matting together very slender and flimsy sub- 

 stances, as straw, chip, and grass to form hats ; and it is on 

 this principle, doubtless, that the ciliary processes are im- 

 pacted or plaited together. 



17. HUMOURS or THE EYE. The humours of the eye 



