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



PLATE LXVII. 



FIG. 29. Brook trout showing noclular growths in FIG. 30. Brook trout showing numerous tumor vege- 



floor of mouth. tations in floor of mouth. 



FIG. 31. Section of floor of mouth showing thyroid follicles growing in epithelium above basal membrane. X70. 



i*l?"^L.r "JOf*' L' f&^ **& : 



FIG. 32. Section from floor of mouth showing histological structure of papillary growths fouiul in floor of mouth 

 illustrated macroscopically by figure 3D. X94. 



