THE NORMAL MODE OF SECRETION IN THE 

 THYROID GLAND 



R. R. BENSLEY , 



From the Hull Labor atory of Anatomy, University of Chicago 



OXE PLATE IX COLOR 



In the glands of the ahmentary canal the process of secretion is 

 associated with definite changes in the structure of the secreting 

 cells, and with the accumulation in them of products, granular 

 or otherwise, which may be interpreted as the organic antece- 

 dents of the secretion itself. Even in some of the internal secret- 

 ing glands, as, for example, the islets of Langerhans of the pan- 

 creas, functioning is associated with the storage or exhaustion of 

 intracellular products which may be similarly interpreted. By 

 means of these secretion antecedents an observer, who has, by 

 experiment and observation, acquainted himself with the secre- 

 tory mode, may form an estimate of the secretory potential at 

 the time of observation. 



In the thyroid gland, on the other hand, the search for such 

 evidences of secretory activity, has been, as regards the nature 

 of the intracellulai; secretion antecedents, of so contradictory a 

 nature, and of such doubtful functional import, that, at present, 

 we are unable to state from the examination of a thyroid gland 

 whether the gland was active or inactive. Accordingly, differ- 

 ent observers, as, for example, in Grave's disease, in discuss- 

 ing the same results, have arrived at diametrically opposed 

 conclusions. 



One of the features of the thyroid gland, in particular, which 

 baffled interpretation was the presence in it of a storage product, 

 the so-called colloid, the route and rate of resorption of which 

 have remained problematical, though chemical and physiologi- 

 cal studies indicated that it contained the physiologically active 



THE AMERICAN JOURNAL OP ANATOMV, VOL. 19, No. 1 



