452 CONJUNCTIVA AND SCLEROTIC. 



conjunctiva by sparing anastomoses only. The superficial 

 plexus is characterised by small and delicate canals which 

 have a very uniform outline. Short lateral, coecal, and more 

 or less pointed or broad, processes are given off from them- 

 The deeper-lying canals, on the other hand, are broader, with 

 more irregular contours, and often present the characteristic 

 constrictions corresponding to valves. Speaking generally, it 

 may be said that the limbus conjunctive possesses a very 

 fine-meshed plexus, whilst the anastomoses, especially of the 

 superficial layers, of the bulb are wider, and, on the other 

 hand, those of the fold of reflection, as well as of the lids, are 

 closer and more numerous. 



The conjunctiva is reflected from the lid upon the anterior 

 surface of the bulb in the form of a thin membrane attached 

 to the adjoining parts by very loose tissue, and thus forms the 

 segment known as the fornix conjunctives. The epithelium 

 that covers this portion of the conjunctival sac differs in many 

 particulars from the epithelium of the connective tissue of the 

 lid. It consists of from two to four layers ; the most superficial 

 are conical, or rather columnar, whilst the succeeding layers are 

 composed of polyhedric or small spheroidal cells. There are 

 no well-marked papillae on this part of the membrane, which 

 differs but little from that of the lid. It contains numerous 

 elastic fibres, as well as branched cells and superficial plexuses 

 of wide capillaries. 



In regard to the conjunctiva bulbi, it only remains to be 

 stated that it is covered by a laminated pavement epithelium, 

 with the same number and kind of layers as the epithelium of 

 the free border of the lid ; the surface of the mucous membrane 

 is not smooth, but exhibits scattered well-developed papillae, 

 which diminish in size and number towards the cornea, and in 

 the immediate neighbourhood of that membrane altogether dis- 

 appear. The epithelium also diminishes in thickness towards 

 the margin of the cornea, where it becomes thinnest, but from 

 thence onwards again becomes thicker. 



The epithelium of the cornea is a direct continuation of the 

 epithelium of the conjunctiva bulbi, though the following 

 points may be regarded as the chief differences between them. 

 The epithelial cells of the deepest and of the middle layers of 



