THE LACHRYMAL GLAND 199 



Fleischer holds that a specihe secretion is pi'odiiced in the 

 ntercalarv duct : 



Das \/()rhaiulen.seiii derartifivr firossc^r Granula in den .Schaltstiick- 

 zcllen, wie ich sie aiich in der Thraricndriise gefunden habe, spricht 

 niit grosser Wahrscheinlichkeit flir eine besondere sekretorische Bedeu- 

 tung dioser Zellen iind zwar muss es sich um eine andere Art von Sekret 

 hanck^ln, als dasjenige, das die Zellen der End-abschnitte auscheidet. 



While I found that the granules in the cells of the tubules — 

 cell type (1) — in well fixed preparations are as large or even 

 larger than those in the intercalary ducts, still certain marked 

 differences do exist between the cells of the intercalary duct and 

 the tubules. The granules in the intercalary ducts are fixed 

 in Zenker's solution while those of the tubules are for the most 

 part not preserved in this solution. When fixed in this solution 

 the granules of the intercalary ducts stain deeply and readily 

 in mucicarmin and muchaematein while the other granule dyes 

 do not affect them. In tissues fixed in Bensley's acetic, bi- 

 chromate osmic solution and stained with anilin fuchsin-methyl- 

 green these granules are stained green while they are not pre- 

 served in the bulging cells of the tubules. 



A narrow band of non-granular cytoplasm is always seen 

 between the cell membrane and the granules. The granules 

 never reach the base of the cells. The cells do not undergo any 

 marked variation in size or shape during their secretory activity. 

 The nuclei remain practically constant in form and position 

 whether the cells are empty or possess numerous granules. No 

 secretory capillaries are present. Frequently, however, inter- 

 cellular indentations are seen. These are some of the features 

 that characterize the cells of the intercalary duct. 



In the tubules, on the other hand, the granules in the majority 

 of the cells are not fixed in Zenker's solution, only those that mark 

 the transition from the duct to the tubule are fixed. The 

 granules when fixed in the height of the secretory stage fill the 

 entire cell and cause it to bulge out. Marked changes conse- 

 quently appear in the form and position of the cell which is true 

 also in the case of the nucleus. Secretion capillaries are also 

 present. 



