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



PLATE XCIX. 



FIG 100 Hybrid yearling salmon. I,arge protruding tumor showing marked change with reversion toward normal 

 type as the result of treatment with iodine added to the water by continuous flow in the proportion of 1 : 5,000,000 

 days. Great visible reduction in size of tumor. Fish 1083. table ix. X86. 



FIG. 101. Section through tumor retrograding as the result of treatment with potassium iodide added to the water 

 by continuous flow in a concentration of 1 : 5.000,000, at the end of 31 days. Large area showing organization by connectiv 

 tissue, previous hemorrhage in substance of tumor induced by treatment. Great reduction in size of tumor. I 

 table ix. X136. 



