Plate CI. 
Bull. U. S. B. F. 1912. 
Fi(i. 1U4. — Control for figrure lUvS. F'isli 1US5. table xn. X86. 
Fk;. 105. — Domesticated brook trout from tlie same lot as figure 104. treated with bicliloride of mercury addetl b>- 
continuous flow to the water in the proportion of 1 : 5. 000. 000 for 14 days. Disappearence of hyperplasia. Marked reversion 
to the normal type. Fish 1084. table xii. X86. 
