DISSECTION OF THE EYE. 93 



8. The Choroid Coat. After removing the retina a 

 good view will be obtained of the choroid. This coat 

 can also be torn off with but little difficulty from the 

 sclerotic, except at the entrance of the optic nerve. 

 Notice the difference in thickness between the two 

 coats. 



THE ANTERIOR HALF. 



Looking into the anterior half, the crystalline lens 

 will be seen through the vitreous humor, and through 

 it the iris and pupil. 



9. The Ciliary Processes of the Choroid. Sur- 

 rounding the lens the anterior portion of the cfioroid 

 coat is thrown into a number of radiating folds, the 

 ciliary processes. 



10. Ora Serrata of the Retina. The retinal coat 

 ends round the periphery of the ciliary processes. The 

 line of demarcation seems quite sharp, but if ex- 

 amined more closely with a lens it will be found to be 

 wavy. This indented margin of the retina is the 

 ora serrata. In reality there is a delicate membrane, 

 continuous with the retina, extending forward from 

 the ora serrata to the tips of the ciliary processes, 

 known as the " pars ciliaris retinae," which is em- 

 bryologically a part of the retina but does not have 

 the true retinal structure. 



11. The Crystalline Lens. Remove as much as 

 possible of the vitreous humor without disturbing the 

 lens ; then with the point of the scissors raise the 

 periphery of the lens from the ciliary processes : the 

 delicate membrane passing from one to the other is 

 the suspensory ligament of the lens. Remove the 

 lens entirely and notice its shape. The posterior sur- 

 face is much more convex than the anterior surface. 



