BLOODVESSELS OF THE EYE. 273 



be completely filled. The whole is then allowed to 

 stand and become cold, that the gelatine may set, 

 after which the eyes are to be carefully excised, and 

 placed in weak spirit. In twenty-four hours this 

 may be increased in strength, and in another twenty- 

 four or forty-eight hours they are to be placed in 

 strong spirit. When they have been in this a day 

 or two the following parts may be prepared : 



Preparation 387 The conjunctival vessels, 

 and the subeonjunctival vessels of the sclero- 

 tic. By making a tangential section from the region 

 of the corneo-sclerotic junction, and after passing the 

 piece so obtained through oil of cloves, mounting it 

 in dammar with the outer surface uppermost, the 

 distribution of the vessels, both in the conjunctiva 

 and, by focussing more deeply, those in the sclerotic 

 at and near the margin of the cornea, is exhibited. 

 Another plan consists in cutting away a small piece, 

 including the whole thickness of both cornea and 

 sclerotic, and mounting in a similar way. The 

 thickness and irregularity of the piece so obtained 

 is a disadvantage, but, on the other hand, the canal 

 of Schlemm and the other venous sinuses may be 

 observed, if the injection has been a successful one, 

 by focussing still lower than for the looped vessels 

 of the sclerotic. 



Preparation 39. Vessels of the choroid and 

 iris. One of the two injected eyes is to be divided 

 by an antero-posterior cut with the razor into a right 

 and a left hand. One of the two halves, the one 

 which does not include the attachment of the optic 

 nerve, is first taken, and the vitreous, retina, and 

 lens removed, so as to clear the inner surface of the 

 choroid and iris. The last-named are next to be 

 separated as one piece of membrane from the scle- 

 rotic. The piece so obtained is then to be again 

 divided into two, by another antero-posterior cut 

 with the scissors, and the resulting halves are to be 

 mounted, after passing as usual through oil of cloves, 

 in dammar, the one with the inner and the other 



