Bull. U. S. B. F. 1912. 



Plate XCIII. 



Fig. ^k. — Wild Wisconsin brook trout. Fed marine fish 12 months. Xorni.d thyroi<l. XS6. 



5 \ .^ c^^^^OSk:* w-^re 





Lit .t "• 



KIG.S9. — Wild Wisconsin brook tront. \'egetable f(_KxI \2 nioutlis. Normal th.\roiil. XS6. 



