408 STUDIES IN ADVANCED PHYSIOLOGY. 



It was in the chapter on heat pointed out in what an 

 important and integral way the perspiration figured in main- 

 taining a constant and unvarying temperature of the body. 



3. Origin of Sweat Glands. In their origin sweat 

 glands, too, are epidermal. They arise in early embryonic 

 life as outgrowths of the epidermis, these down-growths soon 

 becoming hollow and with secondary changes transforming 

 themselves into the adult structure of the gland. 



