INTERNAL AND EXTERNAL SECRETIONS. 



69 



thus, removal or impairment of the thyroid causes myxoedema ; 

 of the suprarenals, Addison's disease ; of the pituitary body, 

 acromegaly. It would seem as if the presence of the internal 

 secretions in the blood afforded stimuli necessary to preserve 



FIG. 31. 



FIG. 32. 



Simple tubular gland. 

 FIG. 33. 



Compound tubular gland. 

 FIG. 34. 



saccular gland. 

 Morphologic types of secretory glands (Dunham). 



Compound or racemose saccular 

 gland. 



a certain tonus and produce definite reactions of the bodily 

 cells. 



Some of the glands with ducts, moreover, seem to produce 



