THE PHYSIOLOGY OF THE DUCTLESS GLANDS 



By N. B. Taylor 

 Department of Physiology, University of Toronto 



[With six plates] 



Thirty years or so ago the study of the ductless glands was a field 

 of practically virgin soil. If we should look into a textbook of physi- 

 ology of that day, we would find the subject disposed of in a very 

 few words. Since then much has been learned and the work that has 

 been done on these hitherto little-known glands is enormous. Each 

 3^ear literally millions of hours of laboratory and clinical work are 

 performed and thousands of papers are written upon the subject. 

 Unfortunately the great bulk of this work is quite barren of any real 

 or lasting value, for just as a ton of rock must be mined and milled 

 in ordef to secure an ounce of gold, or several tons of pitchblende be 

 treated to obtain a gram or two of radium, so an immense amount of 

 work must be done by the laboratory mills in order to recover a few 

 grains of truth. We read, from time to time, in the daily papers, in 

 semiscientific publications, and in the advertising literature of some 

 of the drug houses sensational and glowing accounts of the activities 

 of these glands. But most of these glittering tales are misleading 

 and arise from nothing more genuine than a very vivid imagination. 



The qualifying or negative word " ductless " implies that these 

 glands are peculiar and distinctive in being without ducts. It im- 

 plies also that they were discovered later than the more usual type 

 of gland with ducts. It suggests something new and out of the 

 ordinary. 



A word first with regard to the usual type of gland. These have 

 been familiar to anatomists and physiologists for hundreds of years. 

 Each is composed of a mass of cells arranged in one or other definite 

 pattern so as to form myriads of tiny spherical cavities. On the out- 

 side of the wall of each cavity are blood vessels so that one side of 

 each cell is practically in contact with the blood. From the blood 

 flowing past their doors the cells take what chemical materials they 

 require and with these raw materials manufacture in some mysterious 

 way a very complex substance which they pour into the bowl-like 

 cavities. This material, the gland's secretion, passes into fine hairlike 

 tubes which lead, one from each of the numberless cavities. These 



1 Reprinted by permission from Tlie Scientific Monthly, Vol. XXVII, No. 5, November, 

 1928. The illustrations here reproduced did not appear iu the Scientific Monthly article. 



697 



