BULL. U. S. B. F. 1912. 



PLATE CIX. 



V 



Xr* Xfc., 



r *? * v > - 



FIG. 120. Normal thyroid gland of rat 32 used ns control for rat 115. figure 121. X160. 



'^C 



_,\ r |J? rV jIV 



Ab>*<.^! TT T*V.'JTA ".* 7. IV*. 



f 90 days, from drinking water with suspended set 

 it conducted in Buffalo. X160. 



*-* ^-*-^ f A ^v: r . 



FIG. 121. Hyperplasiaof thyroid in rat at the end of 

 nfected fish troughs from Craig Brook, Maine. Experitneii 



