THE EYE. 251 



removed, care being taken not to rupture the capsule, 

 and placed for a day or two in dilute and then in strong 

 alcohol. It is imbedded in celloidin, and thin sections, 

 made in an antero-posterior direction through the 

 centre, are stained double and mounted in glycerin or 

 balsam. 



Transverse Sections of the Retina. In a perfectly fresh 

 human or pig's eye, one or two small openings are made 

 through the sclera and it is placed in Mliller's fluid ; 

 after a week the eye may be cut across just behind the 

 sclero-corneal junction, and the posterior segment placed 

 in fresh Miiller's fluid. After another week it is trans- 

 ferred for twenty-four hours to dilute, and then put for 

 two or three days in strong alcohol. A small piece is 

 now cut from the retina at a little distance from the 

 optic-nerve entrance and imbedded in celloidin. Thin 

 transverse sections are made, stained double, and mounted 

 in balsam. By this method the general arrangement of 

 the layers is well shown, but many of the finer details of 

 structure are obscure. 



