248 NORMAL HISTOLOGY. 



TECHNIQUE. 



General Dissection of the Eye. For this purpose a 

 large eye, like that of the sheep or ox, is preferable ; it 

 should be opened by a short incision through the sclero- 

 tic, so that the fluid can regularly come into contact with 

 the parts within, and placed in Muller's fluid ; after two 

 weeks it is carefully washed and placed in alcohol for a 

 week, when the dissection may be made. 



The eye should be divided with a sharp razor into 

 lateral halves, the section passing through the optic 

 nerve. The cut surface shows clearly the general rela- 

 tions of the parts ; cornea, iris, lens, ciliary body, vitreous, 

 retina, choroid, and sclera are seen in approximately 

 normal relations to one another. 



If the vitreous be now removed from one of the halves, 

 the retina and ciliary body come more fully into view. 

 As the zonula ciliaris approaches the edge of the lens, 

 it divides into two layers, which pass, one to the anterior, 

 the other to the posterior surface of the body, forming 

 the suspensory ligament ; the slit-like opening between 

 the layers is called the canal of Petit, which may be seen 

 by pulling the lens slightly backward, when the layers will 

 separate. 



Now seizing the half of the lens with forceps and care- 

 fully drawing it downward and backward away from the 

 iris, the zonula ciliaris, in the form of a folded fringe- 

 like membrane, will be separated from the surface of the 

 ciliary body. A portion of this, in connection with a 

 fragment of the lens-capsule, is detached from the lens, 

 Gained deeply in eosin, and mounted in glycerin. After 



