Bull. U. S. B. F. 1912. 
Plate LXV. 
Fig. 25. — Brook trout, showing rectal metastasis of thyroid origin (Anal fin pinned back to show tumor.) 
Fig. 24. — Brook trout, showing large 
round tumor springing from the jugular pit. 
Fig. 23a. — A view of normal floor of 
mouth of adult brook trout. 
Fig. 23 — Hyperemia of floor of mouth of adult brook trout, 
so-called red floor. First macroscopic evidence of hyperplasia or 
carcinoma of thyroid. 
