V.] CONNECTIVE TISSUE. 61 



cesses divide much, but irregularly, and commu- 

 nicate with the processes of other cells. 

 2. Take a frog, of which the brain and spinal cord 

 have been destroyed 1 , squeeze the side of the 

 head gently to make the eye bulge out, then 

 slice boldly at the edge of the cornea ; if it is not 

 completely separated, take up the edge with 

 forceps, and cut through the cornea with scissors 

 at its junction with the sclerotic ; in doing this 

 remember that the success of the preparation 

 greatly depends upon the cornea being placed 

 in gold chloride without having been dragged 

 or pulled about; any blood which may be on 

 the cornea should be removed by placing it in 

 a watch-glass containing normal saline solution 

 and very gently brushing it with a camel-hair 

 brush. Put it in gold chloride *5 p.c. solution 

 for twenty to forty minutes, wash well with 

 water, transfer to water just acidulated with 

 acetic acid, and expose to light 2 . When the 

 cornea has become of a red- or blue-violet colour, 

 put it on a slide with glycerine, and brush or 

 scrape both surfaces to remove the epithelium, 

 then mount in glycerine and examine it under 

 a high power. Where the hexagonal surface 

 epithelium has been removed, there will be seen 

 stained connective-tissue corpuscles, with numer- 

 ous fine branching processes which anastomose 

 with the similar processes of neighbouring cells. 



1 See Appendix. 



2 Probably it will not be stained until the following day. By the 

 tartaric acid method (cp. Appendix) the staining is quicker. 



