98 Eye. 



LENS. 



In cutting sections of the whole eye of frog, good 

 sections of the lens can be obtained. In the whole eye 

 prepared by either of the methods given, the lens will be 

 found hardened, when the eye is opened ; and sections 

 may be cut by the freezing microtome, but they gene- 

 rally break up if thin ; enough, however, can be 

 obtained to enable the student to examine into the 

 structure. 



