THE EMBRYOLOGY OF THE EYE. 6/ 



thelium in the furrow (Fig. 21, A). Farther 

 toward the eye we find an epithelial mass 

 deep in the tissue but still connected with the 

 external epithelium (Fig. 21, B). At a slightly 

 later stage, the mass of epithelium is entirely 

 separated from the external epithelium and a 

 central channel has appeared in it, forming 

 the lachrymal duct. 



The lachrymal gland is formed like other 

 secreting glands by a solid epithelial process 

 extending from the conjunctival epithelium 

 back into the orbit, and giving off branches 

 all of which become hollow tubules. 



The extensive bibliography may be found in the gen- 

 eral treatises of Manz, Kolliker, His, Kessler, and Quain. 



