THE LACIIIIYMAL GLAND 175 



describes these ceineiit structures as bands projecting ihrvn 

 between the cell boundaries completely surrounding; the proxi- 

 mal end of the cell, and states that this structure of the cement 

 is peculiar to the lachrymal gland. I am inclined to think that 

 the basal projecting intercellular cement lines are more or less 

 limited to the angles of the hexagonal cell margins and that they 

 do not form bands or caps surrounding each cell. They are 

 always seen as intercellular continuations of the fine black dots 

 seen at these angles. Cross sections of these ducts show their 

 complete absence between many cells. This would not be the 

 case if they formed true bands. The entire proximal half of the 

 cells would appear in stained sections much darker than the 

 basal half, which is not the case. 



Intercalary ducts. These have been described by many 

 histologists among whom may be named Schwalbe, Bohn and 

 Davidoff, Merkel, and Henle. This duct has been compared 

 to the Speichelrohren (Schaltstiicke) of the salivary glands, 

 especially the parotid. V. Ebner describes these ducts in the 

 submaxillary gland as short blue tubes. Their deep staining 

 characteristics have also been described by Merkel in the lachry- 

 mal gland of the dog; and by Nussbaum and I^angley in the 

 submaxillary of the rabbit. The latter also refers to the presence 

 in them of 'large copious granules.' Zimmermann compares this 

 duct in the lachrymal gland in man with the parotid gland. 

 How^ever, he saw no basal striations in the ducts. According 

 to him the intercalary duct in man is not so well defined as that 

 in the ox but the transition from the intralobular duct to the 

 tubules is much more gradual. Merkel, in his observations on 

 the lachrymal gland of the dog, also describes intercalary ducts 

 but '^fand hier keine Gauge mit Stabchenepithlien. " Ac- 

 cording to him these ducts stain more deeply than the other 

 structures. Regarding the intercalary duct or schaltstiicke, 

 Fleischer states — ''Die Form der Zellen, ihre einschichtigkeit, 

 das enge Lumen, ihr haufiger plotzlicher Uebergang in die 

 Ausfiihrungsgange entspricht ganz dem, was zuerst V. Ebner 

 bei Speicheldnisen als Schaltstiicke bezeichnet hat. Sehr char- 

 akteristich. . . . ist auch ihre diffuse intensive Farbung." 



