BULL. U. S. B. F. 1912. 



PLATE LVII. 



FIG. 3. Rainbow trout. Redrawn from Gilruth's colored original, 1902. Large tumor on each side of branchial 

 junction. Gill fringe distended on surface of lower one. 



FIG. 4a. Yearling hybrid salmon. Massive tumors and marked emaciation. I<ot 19SSa. 



P'IG. 4b. Two year old Sahno sebaso, extreme emaciation. I ot 1950. 



FIG. 4. Salnio foittinafis 2 years old. First external evidence of tumor in base of muscular structure of isthmus, 

 showing marked infiltrative tendency of growth. 



