366 



JAMES ROLLIN SLONAKER 



the posterior canthus. The direction of movement of these 

 secretions is indicated by the arrows. The structure of the 

 nictitating membrane with its marginal plait is such that it not 

 only favors the flow of tears through the lacrimal canal to the 

 mouth, but, in my opinion, actually forces these secretions 

 along. 



Dissection of the lids from the posterior portion of the eye 

 shows the two openings into the lacrimal canals (fig. 8, ol) at the 



Fig. 7 Diagrammatic horizontal drawing of the relation of the glands and 

 their ducts to the eye, the lids and the lacrimal canal leading to the roof of the 

 mouth. Hd, duct of Harder's gland, Hg; L, eyelid; Lc, lacrimal canal; Ld, duct 

 from the lacrimal gland, Lgf N, nictitating membrane; Na, nasal, and T, tempo- 

 ral side of eye; Op, optic nerve. The arrows indicate the direction of flow of 

 the lacrimal secretion. 



anterior angle of the lids, close together and near the margin. 

 That one the upper lid is larger than the lower. A groove^ 

 the peripalpebral groove — extends from each of these openings 

 parallel to the margin of the lids. The upper groove is much 

 deeper and longer, extending along almost the entire margin. 

 It is deepest at the opening and gradually becomes less until it 



