Bull. U. S. B. F. 1912. 
Plate XCVII. 
Ik 
J 
. * 
5W:" 
0- 
f 
L Mf 
Fig. 96. — Marked hyperplasia domesticated brook trout used as control for figure 97. Fish 1040, table ix. X86. 
Fig. 97. — Fish from same lot treated by adding in continuous concentration potassium iodide in the water 1 
Marked regression of hyperplasia at the end of 13 days. Fish 1039, table ix. X86. 
