THE DUCTLESS GLANDS 97 



bohydrate metabolism. While so little can be said oi the 

 exact functions of the adrenal bodies, their importance 

 in our economy is obviously immense, since their entire 

 removal always ends fatally. 



Nothing need be said of the thymus except that its 

 partial atrophy and disappearance at puberty indicates 

 that it is connected with the development of the organs 

 of reproduction. 



The pituitary consists of lobes having different func- 

 tions, if, indeed, they are not separate glands. The hor- 

 mone of the anterior lobe presides over and stimulates 

 growth of the skeleton and perhaps all connective tis- 

 sues; while that of the posterior lobe seems directed to 

 the activity of some glands and to preside over the gly- 

 cogen store in the liver which it appears to dole out in 

 appropriate measure. An extract of the pituitary body 

 called pituitrin excites contraction of plain muscle fiber, 

 so especially marked in the uterus that it has been used 

 in obstetric work to augment uterine power. 



Of the pineal body too little is known positively to 

 justify a statement of its functions, though possibly 

 they are concerned with growth. 



In the pancreas certain masses are found called is- 

 lands of Langerhans. There is some evidence that these 

 furnish an inhibitory chalone which prevents the too 

 rapid use of the glycogen in the liver. 



Not a great deal, it must be confessed, is positively 

 known about the function of the ductless glands. But 

 there is at least enough undisputed to warrant the as- 

 sertion that they are of very great, and, until recently, 

 of unsuspected importance in the general work of keep- 

 ing in repair and regulating many of the most essential 

 organs. When the removal of an organ weighing only 



