412 THE CORNEA, BY ALEXANDER ROLLETT. 



injection, than to exhibit by staining the still preserved nuclei 

 of the protoplasmic plexus torn and broken down by means of 

 the injection. This may be very successfully accomplished by 

 extracting the material that has been driven in. 



To effect this, the cornea injected in the manner above de- 

 scribed should be placed in absolute alcohol. This only colours 

 it slightly, and after a few hours thin horizontal and vertical 

 sections may be made by means of a knife dipped in alcohol. 

 The sections must be placed in aether till the injected fluid has 

 dissolved out, then in alcohol, and finally in water, and examined 

 either immediately or after treatment with staining fluids. 



The fibrillar substance of the cornea is then seen to be sepa- 

 rated into laminae, and the fibrillar bands to be laminated, 

 whilst a regular trellis- work of marginal trabeculse stretches 

 from one to the other with frequent interruptions. 



Passing from such fully injected spots to others in which 

 the injection is just commencing to run, every transitional stage 

 from this condition to the more advanced degrees of forcible 

 separation and splitting may be observed. No better illus- 

 tration of the appearance presented can be given than the com- 

 parison of the fibrillar substance of the cornea to a compressed 

 sponge, which has been made by Kolliker.* 



If we consider the layers of the cornea forcibly separated by 

 the injection to be so re-applied to one another that all the 

 fasciculi of fibrils resume their original position, the fibrils in 

 such a spongy tissue would be arranged as before, except that 

 in the cornea itself they are attached to each other by means 

 of a cementing material. 



We thus believe we have supplied the means by which it 

 may be demonstrated that the ordinary result of simple punc- 

 ture injections is a forcible separation and breaking down of 

 the tissue of the cornea. 



That the meshwork resulting from the forcible separation 

 presents different characters in different animals shows that 

 the fibrils do not pursue the same course in all. 



Schweigger-Seidelf makes the forcible separation of the 



* Mikroskopische Anatomic, Band ii., 2te Halfte, p. 610. 

 t Loc. cit., p. 321. 



