462 



THE EYE IN EVOLUTION 



ciliary body is merely a simple fibrous base-plate of connective tissue 

 (Zimmermann, 1932 ; Bonfanti, 1949) (Figs. 584, 588). In Carnivores 

 the muscle is more fully developed ; both leaves of the ciliary body 

 are provided with meridional muscular fibres, while the inner is pro- 

 vided with radial fibres (Figs. 585, 589). In both of these two classes 



Figs. 587 and 5i 



-The Ciliary Body of Rodents and Ungulates 

 (J. Rohen). 







^■-''*l,-fc;Vii5' 







!<;. 587.— Rabbit (X 92). 



Fig. 588.— Pig [ ■ lilj. 



the cleft is wide and deep ; but in Primates the muscle has developed 

 to such an extent that its meridional and oblique fibres occupy the 

 entire ciliary body ; moreover, its massive anterior attachment to the 

 scleral spur (and through it by the scleral trabeculse to the deeper 

 layers of the cornea) has almost entirely obliterated the cleft leaving 

 only ;i remnant of it at the angle of the anterior chamber (Figs. 

 586, 5. : 



