594 



THE EYE. 



Pig. 401. — Cell-spaces of the Cornea ; 

 Man (Waldeyer). Highly Magnified. 



The figTire is taken from a fresh pre- 

 paration examined i« aqueous humour. 

 In each of the two lower spaces a corneal 

 corpuscle is represented as paitially filling 

 the space. 



these parts the cell-spaces of the tissue are found. These cell-spaces, 

 which are readily demonstrated by staining the tissue with nitrate 



of silver, but also make their ap- 

 Fig. 401. pearauce after a time in the fresh 



tissue without the addition of any 

 reagent (fig. 401), are flattened 

 conformably with the lamellaB, are 

 of an irregularly stellate figure, and 

 freely communicate by their offsets 

 both with others on the same plane 

 and with those above and below. 

 The regularity of arrangement 

 which principally characterises them 

 as compared with the cell-spaces 

 of coimective tissue elsewhere is no 

 doubt dependent on the laminated 

 structure of the cornea. 



The corpuscles of the tissue — 

 corneal corpuscles — lie within these 

 cell-spaces, corresponding generally 

 with them in fonn, but without 

 entirely filling them, the room left 

 serving for the passage of lymph 

 and leucocytes. The protoplasm of 

 the corpuscles is clear and hyaline, except in the neighbourhood of the 

 large nucleus, where it is granular ; they send long branching processes 

 along the anastomosing canals of the cell-spaces, which in some 

 cases appear to join with those of neighbouring corpuscles. In ver- 

 tical sections they appear fusiform (fig. 400, c), but horizontal sections 

 .show them to be flattened conformably with the surface. Exammed 

 on the warm stage, the corpuscles are said to exhibit slow amoeboid 

 movements in the form of protraction and retraction of their processes. 

 These, however, are not to be confounded with the more active move- 

 ments of leucocytes which may be traversing the space. 



In the human cornea the cell-spaces can be filled -^v-ith fluid injection by 

 sticking the muzzle of a fine syringe into the tissue, and employing a, very low 

 pressure ; in this way a network of anastomosing stellate figures is obtained 

 (Recklinghausen's canals) : if, however, the injection-fluid be too consistent, or 

 if too great force be employed, the injection becomes extravasated in the inter- 

 stices of the fibril bundles, the direction of which it takes ; and the ajipearance 

 is produced of minute swollen tubulai- passages lainning at right angles to one 

 another in the difi^erent layers (Bo■v\^nan's corneal tubes). This appearance may 

 .still more readily be obtained if air is injected into the tissue instead of mercury 

 (the fluid used by Bowman), and it is seen that the injection always stops at the 

 margin of the cornea, where the tissue becomes denser as it passes into the 

 sclerotic, whereas Recklinghausen's canals are continued into the cell-spaces of 

 the latter. 



The part of the cornea immediately beneath the anterior epithelium, 

 for a thickness of from g-o^oo ^^ t-^Vtj of ^'^ moh, is denser than the 

 rest of the tissue, and entirely free from corpuscles (fig. 400, 2). It was 

 named the anterior elastic lamina by Bowman, but appears not to differ 

 materially in structure from the rest of the corneal substance, fibres 

 from which may be seen passing obliquely towards, and becoming lost 

 in it (binding fibres) (fig. 400, a). 



