LIFE HISTORY OF DESMOGNATHUS FUSCA. 33 1 



gc, giant cells of the acinous glands. 

 int, inner layer of epidermal cells. 



intr, intrusive cells (Schaltzelle), which project from the deeper layer into the 

 outer layer. 



Ic, Leydig cells. 



leu, leukocytes. 



lu, lumen of gland. 



ml, moult layer. 



ml, mitosis. 



mt(inv), mitosis in a cell which has invaded a Leydig cell. 



pg, pigment. 



pgbr, branches of pigment cells. 



pgc, pigment cells. 



pgc(inv), pigment cells which have invaded the Leydig cells. 



pgg, intracellular pigment granules. 



sn, integumental sense organ. 



sp, spireme. 



yg, yolk granules. 



DESCRIPTION OF PLATES. 



PLATES I., II., and III. A series of outlines drawn with Abbe camera, magni- 

 fication X 4.25, showing various stages of Desmognathus fusca from the time of hatch- 

 ing to the attainment of practically adult proportions. 



PLATES IV., V., and VI. Sections of the skin of Desmognathus fusca, showing 

 the structures characteristic of the various periods and the developmental changes 

 which take place in the transition from one stage to another. Drawn with Abbe 

 camera. X 45. 



ERRATA. 

 References throughout the text to PI. I., Fig. 7-11, apply to PI. II. 



