406 



THE CORNEA, BY ALEXANDER ROLLETT. 



A freshly excised cornea immersed in the aqueous humour 

 of the same eye is made to form a bridge between two platinum 

 electrodes, and is covered with a piece of thin glass, to the 

 margin of which a little fat has been applied. A few opening 

 shocks are then slowly applied, as above mentioned, and very 

 soon the previously homogeneous or only faintly perceptible 

 radiated corpuscles of the cornea make their appearance, and 

 such an appearance as is represented in fig. 385 is seen. 



Looped or straight, elliptic, fusiform, or round figures, come 

 into view. The round and elliptic ones have the appearance 

 of sharply defined cavities. 



Fig. 385. 



Fig. 385. From the cornea of a Frog irritated by means of strong 

 induction shocks (highly magnified). 



These clear figures are only the longitudinal, oblique, or 

 transverse sections of the intercommunicating system of cavities 

 traversing the cornea, in the dilated nodal points of which are 

 the nucleated central masses of the radiated corneal corpuscles. 

 This is clearly shown if we try to focus sharply a corneal cor- 

 puscle ; for it is then seen, as in fig 385, that the finely granular 

 protoplasm of the corpuscle is retracted from the walls of the 

 wider cavity in which it lies, though it still resembles the 

 cavity in its general form, and some attenuated processes from 



