Scale of wild rainbow trout 

 in its second year of 

 growth, captured in Madison 

 Biver on September 1, 1955. 

 Trout was 8.0 inches in 

 total length. The distinct 

 annulus half way out on the 

 scale is typical of all wild 

 rainhow scales examined. 



Scale of marked rainbow trout 

 planted in Madison River 

 in 1955 from Ennis Hatchery. 

 Trout was 13.0 inches in 

 total length at capture on 

 June 15, 1955, and had been 

 in the stream only a few 

 days. 



Figure 2 ,-- Scales of wild and hatchery rainbow trout showing 

 differences in circulus patterns . 



