CUTANEOUS APPENDAGES 



273 



fusiform fibers whose nature is somewhat doubtful, though they have 

 been most frequently considered to be smooth muscle fibers. These 

 fibers are frequently branched, their processes often extending between 

 the cells of the secreting epithelium nearly to the lumen of the gland. 

 The secreting epithelium of the fundus consists of tall columnar 

 cells which possess a large spheroidal chromatic nucleus and a finely 

 granular cytoplasm. The basal portion of their cytoplasm is often 

 slightly rodded and the cells are so closely pressed together that it is 

 frequently impossible to distinguish their outlines. The secreting cells 

 are disposed in a single layer and, except after active secretion, are so 





FIG. 267. SEVERAL COILS OF A SUDORIPAROUS GLAND OF THE HUMAN FINGER. 



a, secreting portions, their lumen containing traces of secretion; b, ducts; in, muscle 

 cells. Hematein and picrofuchsin. X 550. 



tall as to leave only a very narrow, central, glandular lumen. During 

 secretory activity the cells become shrunken and their cytoplasm more 

 granular. After a period of rest the cytoplasm again becomes clear 

 and vesicular in appearance and the cells are much distended. The 

 secretion reaches the lumen through intra- and intercellular canaliculi. 

 The ducts are lined by a double, occasionally triple, layer of some- 

 what flattened epithelial cells, which rest upon a delicate membrana 

 propria continuous with that of the secreting portion. The gross di- 

 ameter of the duct is much less than that of the secreting portion of 

 the gland, yet the lumen of the duct may be larger. That portion 

 of the duct which is lined by the thin stratified epithelial layer pursues 

 a spiral course through the subcutaneous tissue and the derma. Tt finally 

 18 



