PROPER TISSUE OF THE CORNEA; INTERFIBRILLAR MATRIX. 415 



spaces with the length of the flat middle portion of the corneal 

 corpuscles, we shall find that the former are much larger 

 than the latter. There must therefore be deposited within and 

 around the cavities containing the corpuscles and separating 

 the fasciculi from each other, a broad thin layer of that sub- 

 stance extended parallel to the corneal surface, whilst it occurs 

 also finely divided in the smaller passages between the fibrils, 

 and around the processes of the corneal corpuscles running in 

 the direction from one surface of the cornea to the other 

 (fig. 380, 6). In coincidence with the peculiar arrangement 

 and distribution of the corneal corpuscles and the fasciculi of 

 fibrils (compare figs. 377 and 380, 6), these large flat layers 

 of intermediate substance run in general in the direction of the 

 corneal surfaces, and, being inclined towards each other, coalesce 

 and are connected by variously formed laminae and striae. 



Specimens may also be prepared by teasing out the tissue 

 of the above-mentioned (p. 404) corneae, which have been first 

 silvered, and then subjected to the action of gold. The several 

 fasciculi of fibrils then frequently exhibit the indication of the 

 contours of the still uninjured or, owing to the effect of the 

 needles, disrupted corneal cavities. The fibrils themselves, 

 where they have become completely isolated, are smooth, and 

 are either not at all, or only feebly, stained. The blue colour 

 adheres to a mass which appears to be traversed by the fibrils ; 

 this mass seems to be beset with granules, and thus, as it on 

 the one hand surrounds the fibrils, so does it form on the 

 other the proper walls of the cavities. 



The above-mentioned skeleton of cementing substance can 

 be isolated from the fibrils of the cornea, though in a distorted, 

 variously torn, and collapsed condition, and this may be 

 accomplished by converting the corneal fibrils into gelatine 

 by prolonged boiling in water or in alcohol acidulated with 

 hydrochloric acid (strong alcohol, containing from 0'5 to 075 

 per cent, of fuming hydrochloric acid). 



In the cornea of the Ox, Dog, and Sheep, no other change is 

 observable besides the already mentioned sudden alteration of 

 form which occurs immediately on boiling the cornea with 

 the acidulated alcohol. The corneal fragment, however, be- 

 comes progressively freed from the soluble gelatine-yielding 



