8 



By the contractions of this muscle, it plays an important 

 part in accommodating or adjusting the eye to the perception 

 of objects at different distances. 



The ciliary body forms a ring which overlaps before and 

 behind the ciliary muscle and lies between the choroid and 

 iris, or rather it connects the choroid to the iris. 



The ciliary processes consist of 110 to 120 radiating folds 

 formed by the plaiting and folding inward of the choroid at 

 its anterior margin; these are received between the corres- 

 ponding folds of the suspensory ligament of the lens. 



The dark color of the choroid is due to the coloring mat- 

 ter, pigment in the cellular or internal layer of this mem- 

 brane. The pigment absorbs the rays of light which pass 

 through the retina and thus prevents their becomiog re- 

 flected and confusing the vision. The brilliant metallic col- 

 ored tapetum is generally observed in nocturnal animals 

 (horse, etc.), and especially in the carnivora. It is believed 

 that by reflecting rays of light a second time through the 

 retina, it gives the animal a clearer and better vision at 

 night. 



This is the cause of the glare or "balls of fire" perceived 

 in the eyes of the cat and other carnivora in the dark. 



Fig. 2. 

 Normal Horses Eye (after Goubaux and Barrier). 



