328 Effa Funk Muhse. 



After having occupied a place in the two or more cell layers of the 

 transitional stratum, they become lifeless material, the molt, which is 

 j)eriodically cast off. (Figs. 2-4, 19, 25, 33, 48, 49.) 



Beaker cells. One celled glands, called beaker cells, aid in this 

 process of molting, as was early stated by Schultze ('67) for Ba- 

 trachians in general. In the adult toad these beaker cells are the 

 only glands located wholly within the epidermis. They are situated 

 at intervals in the upper part of the transitional stratum and differ 

 from surrounding cells in shape and appearance. (Figs. 1, 2, 3, 

 48.) The bodies of these cells may lie at any depth among the two 

 or three outer layers of the transitional stratum They connect 

 with the surface of this stratum by means of a more or less slender 

 neck, which has an opening at the upper end. The body of the cell 

 is almost entirely filled by a nucleus whose chromatin is collected 

 in a few masses. Two nuclei in a cell have been observed. The cyto- 

 plasm of a beaker cell is much clearer when stained than that of 

 surrounding ones. These cells have been met with in all regions 

 of the epidermis, ventral skin, ordinary skin of the back and the 

 epidermis over the parotids and other warts of the back and legs. 

 They are often so slender that in cross section, the body of such a 

 cell is but little larger than the nucleus of an ordinary cell. They may 

 lie between two cells or at the angle of several. Their distribution 

 varies. A section horizontal to the epidermis, from a parotid, shows 

 them to occur in about the proportion of one beaker cell to three 

 ordinary cells if we consider but one layer of cells. (Fig. 1.) In 

 another individual, a vertical section of ordinary skin showed 

 eighteen such cells within a distance of 5 mm. (Fig. 3.) At the 

 opening of a beaker cell, an accumulation of granules is frequently 

 noted lying between the transitional and molt strata. Occasionally at 

 these points the molt stratum is raised and freed for a considerable 

 distance. Everything points to the conclusion reached by Schultze 

 and later by Schultz ('89) that these cells are one-celled glands, 

 whose secretion loosens the molt from the transitional stratum. 



Epidermis relative to the regions of the body. The epidermis 

 reaches its maximum thickness over the parotids. This is due both 

 to the larger size of the cells and to the greater number of cell layers. 



