194 JOHN SUNDWALL 



1 under the various stains — completely filled mth granules and 

 bulging, lumina of the tubules not visible. 



B. A medium granular stage in which the tubule possesses for 

 the most part cells of the types described as types 2 and 3. 

 Rarely does one find an entire tubule made up of these types 

 alone, as bulging cells of type 1 are generally present. It will 

 be recalled that type 3 cells are those described as cylindrical, 

 pyramidal, or crescent cells filled with deeply stained granules. 

 The nuclei of these cells are still round or oval and separated 

 from the base of the cell. This type doubtless represents an 

 earlier phase to that of type 1 in the stage of granule formation. 

 Granules have formed in sufficient quantities to fill the cells but 

 not to such an extent as to enlarge them — cause them to bulge. 



Cells described as type 2 in all likelihood represent two phases 

 in secretion, a) Those which possess few granules at their 

 proximal ends suggest the terminal phase of secretion wherein 

 the granules for the most part have passed out of the cells. 

 b) Those in which comparatively few granules are seen scattered 

 throughout the cells suggest cells in the beginning phase of granule 

 formation. These granules stain with varying intensities. Some 

 are large and pale, others small. There is no regularity to their 

 distribution. The few nongranular cells may be interpreted as 

 occupying a position between the terminal of granule expulsion 

 and the beginning of the formation of new granules. The very 

 few nongranule cells seen and the fact that the type 2 cells 

 usually possess granules both at the lumen end of the cell (term- 

 inal secretion) and also a few granules throughout the cytoplasm 

 (beginning granule formation) strongly suggest that the extrusion 

 of granules and the new formation of granules go hand in hand 

 in the same cell during the normal secretory activity of the gland. 

 We have then in this gland a continual secretion as indicated by 

 the cells showing all phases of secretory activity. 



C. In the third group of glands the secreting cells were much 

 reduced in size, the lumina wide and open, the few granules 

 present confined to the proximal end of the cell, and the nuclei 

 round and oval. This condition was uniform throughout the 

 gland and simulated preparations obtained by other observers 



