Bull. U. S. B. F. 1912. 



CIX. 





KiG. 120. — Normal thyroid gland of rat 12 used as control for rat 115. figure 121. X16' 



\\>,. 1_1- -ll.v i^vipi.i-.io ui thyroid in rat at the end of 90 da>s. from drinking water wiili suspended scri\pinK:s fiuui 

 infected fish troughs from Craig Brook. Maine. Experiment conducted in Buffalo. X16U. 



