THE LACHRYMAL GLAND 189 



alcohol bichromate solution (Technique IV, 2 a) and by formalin 

 bichromate sublimate solution (Technique IV, 2 c). Tissues 

 must be small as the penetration of these solutions is not great. 

 In these solutions the granules of both the tubules and the 

 intercalary ducts are preserved. These are readily stained with 

 muchaematein (Technique V, 1), mucicarmin (Technique V, 2) 

 iron haematoxylin, iron haematoxylin counterstained with 

 mucicarmin, copper chrome haematoxylin (Technique V, 5) neu- 

 tral gentian (Technique V, 6) and safranin-acid violet (Tech- 

 nique V, 7). 



Mucous stains. Sections fixed in Bensley's sublimate alcohol 

 bichromate solution or in formalin bichromate sublimate solu- 

 tion when stained with muchaematein or mucicarmin show 

 that the selective staining is confined entirely to the granules 

 of the tubules and ducts. The various types of cells as seen in 

 these sections depend upon the secretory state of the gland at 

 the time of fixation. The various stages described in the tubules 

 of fresh tissue are seen in these preparations and may be grouped 

 as follows : 



(1) Large rounded or bulging cells completely filled with 

 intensely blue stained granules — type 1. All other structures 

 within these cells are obscured as a rule. Frequently, however, 

 flattened nuclei are seen at the base. These cells correspond to 

 those described in both fresh tissues and in Zenker's muchae- 

 matein sections. In the latter case the granules were not stained 

 but the intergranular network was prominent as a consequence 

 of a light blue stain. 



(2) and (3) Cells more or less cylindrical or pyramidal in 

 outline, or appearing as demilunes in the periphery of the tubules 

 completely shut off from the lumen by the large bulging cells — 

 frequently the cylindrical cells are constricted in their vertical 

 axis by the pressure of the bulging cells and thus simulate in 

 outline hour glasses. The nucleus is generally round or oval and 

 does not lie directly on the base of the cell but is separated from 

 it by a narrow zone of cytoplasm. These cells can be divided 

 into two classes. The one contains relatively few or, rarely, 

 no granules. The granules are. seen in the proximal end of the 



