222 



MANUAL OF HISTOLOGY. 



which is shrivelled. Swelling up of the tissue, on the other hand, renders 

 these delicate fibres invisible in a moment. The system of canals (fig. 

 216, a) has been erroneously taken by many to be a system of retiform 

 cells, the corneal corpuscles, and indeed it is deceptively like something 

 of the kind when treated with dilute acids. It always occupies with its 

 accessories the spaces between the bands of the ground-substance, and 

 appears as a ramifying system of tubes, capable of isolation by means of 



Fip. 216. Cornpal corpuscles, a. from the ox, as seen from the surface; 6, from 

 an infant (surface) ; c. side view of the same from a child four months old ; c?, from 

 small embryos of the human being and ox. 



boiling and maceration in strong mineral acids. That it is in reality 

 hollow is indicated by the fact that morbid growth and deposits of fat and 

 pigment take place in it. Artificial injection of the cornea by puncture 

 (Bouman, Recklinghausen, Leber, C. F. Mullcr, Schweigger-Seidel\ 

 generally gives rise to a rupture of the tissue (Rollett), and produces 

 various appearances in it. The canal-work of the so-called corneal 

 corpuscles appears also to be capable of being filled however (Boddaert). 

 This system of canals, which possesses probably a modified parietal layer 

 (extremely extensible, and certainly not everywhere continuous), has far 

 wider meshes in the adult than in the infant or foetus. 



Seen from the surface, its characters are those of a network possessing 

 widened radiating nodal points of considerable magnitude (fig. 216), while, 

 in profile, it presents longitudinal and usually fusiform enlargements, 

 running parallel with the bounding lines of the cornea. The former 

 stand in communication with one another by means of fine passages, and 

 at times also with those of the deeper or more superficial series, through 

 ascending or descending lines. These stellate enlargements are, therefore, 

 flattened in a direction perpendicular to the surface of the cornea. 



As to the size of these points or of the corneal corpuscles, their 

 length is stated at 0-0135-0-0180 mm., and breadth at 0-0102-0'0124 

 mm. Their processes have a diameter of about 0-0023-0-0007 mm. 



