The Cutaneous Glands of Common Toads. 347 



homogeneous, another reticular and another granular. Even a cell 

 may exhibit one kind of secretion in its upper region and another 

 in its lower (Fig. 50). 



I have found many stages between what I have described under 

 d and e. The glands referred to as d and e, and which make up 

 the larger glands of the outer battery, measure on the average 96 

 microns in depth and 160 microns in transverse diameter. 



II. The glands of the transitional battery are often not present 

 in an area at a given time. But when these intermediate forms are 

 present, there is no sharp dividing line between them and the outer 

 and inner batteries. As said before, I have divided glands into 

 these three batteries merely for convenijence. In shape, the acinus 

 of transitional glands tend to elongate in depth. The collar becomes 

 somewhat conical in shape. The neck becomes relatively shorter. 

 But it is more particularly in the epithelium, secretion and lumen, 

 that the transition from young to mature glands is apparent. 



(f) A stage in advance of the last spoken of (e), is shown by a 

 gland in which the acinus is somewhat elongated, and the epithelial 

 cells in its lower half are greatly increased in height. The nucleus 

 of each cell is crowded toward the edge and the cytoplasm of the 

 cell is granular, presenting the same granular appearance as the 

 secretion of adjacent mature glands. The cells about the upper 

 part of the acinus remain cubical in form with homogeneous cyto- 

 plasm. The lumen is still free from secretion (Figs. 36, 37). What 

 appears as drops of secretion in the lumen, and probably what has 

 been so described, are but the cut ends of cells, which have extended 

 further into the lumen and because of the weight of the secretion are 

 bent over at an angle. 



(g) Further advance is shown by a gland in which even the cells 

 of the upper part of the acinus have elongated. The cytoplasm of 

 the epithelial cells about the neck is reticular, and stains exactly 

 as do part of the cells in neighboring glands of the outer battery ; 

 that of the remaining cells is faintly granular. The lumen is almost 

 filled with a secretion similar to the cyptoplasm in the last-mentioned 

 cells (Figs. 38, 39). 



There is considerable difference in dift'erent individuals. A 



