THE CORPUSCLES OF THE CORNEA. 383 



corneal corpuscles still more distinct. The close agreement in 

 the co-efficients of refraction of all the elements of the fresh 

 cornea is thus gradually lost after excision. At first the cor- 

 puscles can be only discovered with difficulty and in parts, but 

 subsequently they become much more distinct. The cornea of 

 the Frog, taken from eyes that have been preserved for a con- 

 siderable period in a moist chamber, are especially well adapted 

 for the demonstration of the corneal corpuscles.* 



Fig. 379. 



r^-- r ; = ~~^-ST T ~ 



Bi 



Fig. 379. Corpuscles of the cornea, from the recently excised cornea 

 of the Frog, preserved for twenty-four hours in the fold of the mem- 

 brana nictitans. The corpuscles and processes represented all lie 

 on the same plane. 



When the excised cornea of the Frog has been preserved for 

 twenty-four hours in the fold of the membrana nictitans,f 

 the corpuscles appear as they are represented in fig. 379. 



In such specimens, by different focussing, the whole plexus 

 formed by the corpuscles traversing the cornea may be readily 

 followed. 



An excellent method of exhibiting the cell-plexus in the 

 cornea consists in the application of chloride of gold.{ A 



* Kiihne, loc. tit., pp. 130 and 131. 



t Strieker, loc. tit., p. 36. 



J Cohnheim, Virchow's Archiv, Band xxxviii., pp. 346349. 



