THE LACHRYMAL GLAND 179 



characteristic granular stain. The presence of nongranular 

 cells in the intercalary duct is plainly seen in cross sections of 

 those ducts, the number of unstained cells varying in different 

 sections. In some ducts only one cell may be present which 

 does not possess the muchaematein stained granules, again such 

 ducts are seen where the majority of the cells in cross sections 

 are not stained. As a rule, however, most of these cells possess 

 specifically stained granules. 



At the origin of the intercalary ducts from the intralobular 

 ducts the granules as a rule make their appearance in the first 

 cells as a narrow layer in the lumen surface of the cell, having 

 the appearance of a theca or cuticula. As the distance from 

 the intralobular duct increases this stratum of granules widens 

 until it occupies the entire proximal half of the cell. The com- 

 plete transition from the normal amount to the complete dis- 

 appearance of granules takes place in from four to seven cells. 

 Frequently one sees an abrupt transition at the junction of the 

 intercalary and intralobular ducts. In this type the granules 

 in the cells of the intercalary duct remain normal and constant 

 in quantity until the intralobular duct is reached when they 

 disappear completely. Thus two neighboring cells may be seen 

 one belonging to the intercalary duct and having the characteris- 

 tic granules occupying the proximal half of the cell while the 

 bordering cell belonging to the intralobular duct possesses no 

 granules whatsoever. The granules in the intercalary duct are 

 seen to extend to the tubules. They are readily seen in sections 

 prepared by Weigert's method (Zenker's fixation) for the dem- 

 onstration of elastic fibres. In the alcohol osmic bichromate, 

 and methyl green anilin fuchsin preparation, the granules are 

 well preserved and stain green. 



Tubules. The cells of terminal tubules vary in size and form 

 depending upon the stage of secretion they are in. Thus they 

 may be columnar, cuboidal, oval, polyhedral, pyramidal, spheri- 

 cal, or flattened. When the cells composing these elements are 

 in the height of the granular stage the cells are large and bulging 

 and the secreting end may then appear as an alveolus or acinus. 

 Again when the cells are observed in a partial granular stage 



THE AMERICAN JOURNAL OP AJ^ATOMY VOL. 20, NO. 2. 



