Plate C. 



Fig. 1(12. — Control for fiKure In'. I'isli HWii. table xii. XS6. 



I-'li,. 111.^. — Doinesticnteil brook trout Irom the same lot as Jiijnre 1(L'. treated with bichloride of mercnr.\' acUieti b.v 

 contiimous flow to the water in the proportion of 1 : .S.iMI.UOO for 12 da.v.s. Disappearance of hyperplasia. Marked reversion 

 to the normal t.vpe. Fish Ui89. table xii. XS6. 



