52 R. R. BENSLEY 



mode of secretion comes in, and the product of secretion is con- 

 densed and stored in the intrafoUicular cavity. It is conceiv- 

 able, of course, that other factors than excess of production over 

 functional needs might bring about this result, as, for example, 

 an agent inhibiting direct export from the cell, or mechanical in- 

 terference with the outflow from the cells. The latter influence 

 is w^ell illustrated in the colloid adenomata where, notwithstanding 

 the fact that the stroma may be hyaline, the cells contain abun- 

 dant colloid spherules, and thus give, according to the old criterion 

 of Hiirthle, the impression of high secretory activity. According 

 to my hypothesis of thyroid secretion, this condition would rep- 

 resent a slow secretory activity of the epithelium of the tumor, 

 all of the energy of which is, however, devoted to storage, since 

 direct export by way of the vascular channels is impossible. 

 This may explain the difference noted by Marine between the 

 hyperplastic gland and the adenoma as to susceptibility to influ- 

 ence by iodine. The hyperplastic gland, whether its activity be 

 high or low, is exporting its product directly. Iodine whether 

 by accelerating the activity of the gland and so producing a con- 

 dition of physiological saturation with thyroid products, or by 

 actually inhibiting the export of material from the cell, causes the 

 cell to reverse its processes, and store it in the follicular cavities. 

 The adenoma is already storing all of the product which the 

 vascular conditions and its specific cell equilibrium permit it to 

 form, and so the process can not be influenced by iodine. 



According to this conception of thyroid secretion the colloid 

 in the thyroid vesicles is per se no measure of the activity of 

 the gland at the moment of observation, though its consistence 

 and its qualities may offer valuable indications of the capacity 

 of the thyroid cell for normal storage. The colloid in fact may 

 be the product of a storage phase which preceded the examina- 

 tion of the gland by a considerable period of time, since it is 

 necessary to assume the resorption of this material only under the 

 conditions where the normal direct secretory activity of the gland 

 is insufficient to meet the functional demands. Accordingly, 

 also, lack of colloid in the gland does not necessarily mean de- 

 pression of the gland activity below the normal rate at the time 

 of observation, though it probably does mean that there is such a 



