286 



THE ADRENAL SYSTEM AND VASOMOTOR FUNCTIONS. 



of the process are as follows: The cells next the marginal cells 

 (Fig. 1, b) increase in size and their nuclei dwindle. As they 

 approach the center of the acinus their nuclei disappear, and 

 the cells become distended with granules and oil-globules. 

 Finally they burst and their debris forms the secretion, which 

 is discharged." This also coincides with the manner in which 

 sudoriferous glands produce their secretion. 



"Lactation is the outcome of a similar process," continues 

 Mr. Williams. "Milk must, therefore, be regarded as the 

 product of the deliquescence of successive degenerations of 

 epithelial cells which are destroyed in this process and replaced 

 by relays of new cells derived by division from other still active 



FIG. 1. HlSTOLOGICAL SECTION OF THE WALL OF A SEBACEOUS 



CYST. (Cornil and Ranvier.) 



a, Fibrous stratum with connective tissue corpuscles, b, Marginal 

 stratum, c, Hornifying cells, d, Sebaceous cells. 



epithelial cells of the part. Thus we see that growth, devel- 

 opment, and secretion are but slightly varied manifestations 

 of cellular activity finding expression in different ways." 

 . . . "The complete degree of mammary function that 

 eventuates in lactation is only attained periodically, and the 

 process is always gradual. The following is a brief account of 

 Creighton's description of it: Subsidence of the function goes 

 hand in hand with undoing of structure, and revival of the 

 function with the building up of structure. Variations of 

 intensity in the secretory force are measured by its products 

 which correspond to changing aspects of the secreting acini. 

 The beginning of the rising function coincides with the be- 



