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



PLATE XCIV. 



.1 V 

 \ V! <\ 



v^ 



FIG. 90. Low power section at median line through thyroid region of wild Wisconsin brook trout, showing well- 

 developed carcinoma of the thyroid infiltrating surrounding structures, bone and cartilage. After 18 months raw liver 

 feeding at Craig Brook. Experimental induction of carcinoma of the thyroid. X13. 



