THE EYE. 393 



more cylindrical, whilst others, particularly towards the point of 

 reflection of the membrane where it is generally thicker, are 

 larger, (as much as J,'" long), more verrucose and fungiform. 

 At the line of reflection itself, Krause describes minute race- 

 mose mucous glands, J — ^'" in size, but which do not always 

 exist. The conjunctiva sclerotica, is white, less dense and 

 thinner than that of the lids, tolerably rich in fine elastic 

 fibres, and loosely and moveably attached to the sclerotic by an 

 abundant submucous connective tissue, containing more or 

 fewer fat-cells. Papilla are wholly wanting in this portion, 

 except at the line of reflection, as well as glands, whilst the 

 epithelium is well developed, as on the conjunctiva cornea, and 

 beneath it there is not unfrequently an outermost layer of the 

 proper mucous membrane, in the form of a very distinct struc- 

 tureless, narrow seam. At the margin of the cornea, particu- 

 larly in elderly persons, the conjunctiva sclerotica forms a slight 

 annular elevation \ — V" broad, — the annulus conjunctiva, which 

 encroaches a little upon the cornea at the lower, and especially 

 at the upper border. The corneal conjunctiva has been already 

 described, and it only remains to notice the plica semilunaris, 

 or the third palpebra at the inner canthus of the eye. This is 

 a simple duplicature of the sclerotic conjunctiva, which rises in 

 front into a conical elevation — the caruncula lachrymalis, — in 

 which are seated about a dozen fine hairs, surrounded by an 

 equal number of rosette-like sebaceous follicles \ — jf" in size, 

 encompassed by numerous fat-cells. 



The lachrymal apparatus consists, in the first place, of the 

 lachrymal glands — a certain number of larger and smaller com- 

 pound racemose glands, disposed in two groups — termed the 

 superior and inferior lachrymal glands, and in the structure of 

 the larger and smaller lobules, as well as in the rounded gland- 

 vesicles, 0*02 — 0-04'" in diameter, precisely resembling the sali- 

 vary and mucous glands (§§ 134, 135). The excretory ducts of 

 these glands, 6 — 12 in number, perforate the conjunctiva in 

 the fold between the outer part of the eye-lid and the globe of 

 the eye; they are excessively fine canaliculi, composed of connec- 

 tive tissue, with a few nuclei and elastic fibrils, and of a cylin- 

 drical epithelium. It is extremely difficult to display these 

 canals in man, whilst in animals (the Ox, for instance) they 

 are easy of demonstration. The passages by which the tears 



