SEAWARD MIGRATION OF CHINOOK SALMON. 73 



Fig. 5. — Fry from under cannery at Ilwaco, Wash. October 26, 1914. Sex not determined. 141 

 mm. The intermediate band is composed of unusually wide rings, characteristic of fish found imder 

 the canneries. The band of narrow rings preceding the intermediate band is conspicuous. 



Fig. 6. — Fry from same collection as figm-e 5. Sex not determined. 166 mm. Similar to figiu-e 

 S, except that the intermediate band is not preceded by a distinct band of narrow rings. 



Fig. 7. — Fry from same collection as figure 5. Female, 145 mm. The check preceding the inter- 

 mediate band (which is not strongly differentiated) is intermediate between the conditions illustrated 

 in figuxes 5 and 6. 



Plate III. 



Fig. I. — Yearling from Deer Island, Columbia River. April 13, 1916. Female, 103 mm. Showing 

 marginal winter band and no primary check. 



Fig. 2. — Yearling from Crandall's seining ground, Grims Island, Columbia River. March 31, 

 1916. Male, 92 mm. Similar to figure i, except for the primary check. 



Fig. 3. — Yearling from same collection as figure i. Female, 99 mm. A typical scale characteris- 

 tic of the spring yearling migrants, showing an intermediate band preceded by a distinct winter band 

 of narrow rings. No primary check present. 



Fig. 4. — Yearling from same collection as figure i. Male, 113 mm. Showing intermediate band 

 and also primary check. 



Fig. 5. — Yearling from Clackamas River. June 3,1916. Male, 105 mm. Showing well developed 

 new growth of the second year. 



Fig. 6. ^-Sacramento River fry from Walnut Grove, Calif. April 9, 191 1. Male, 75 mm. 



Fig. 7. — Sacramento River fry from Butte Slough. June 8, 1911. Male, 97 mm. 



Fig. 8. — Sacramento River fry from near Butte Slough. May 9, 191 1. Male, 103 mm. Showing 

 intermediate growth. 



Fig. 9. — Fry from McCloud River. July 24, 1909. Mature male, 128 mm. Showing marginal 

 winter rings. 



Plate IV. 



Fig. I. — Yearling from McCloud River. January 22, 1912. Male, 142 mm. Showing marginal 

 winter band. 



Fig. 2. — Yearling from same collection as figure i. Male, no mm. Showing two wide marginal 

 rings of the new growth of the second year. 



Fig. 3. — Yearling from Brookdale hatchery, Calif. January 4, 1913. Female, 127 mm. Showing 

 irregularities of growth characteristic of the scales of hatchery fish. 



Fig. 4. — ^Yearling from Bonneville hatchery, Greg. March 2, 1915. Male, 162 mm. The winter 

 band is not strongly defined, but the new growth is well started. 



Fig. 5. — Yearling from Bonneville hatcher>', Greg. July 7, 1916. Male, 150 mm. This fish was 

 one of the mature males marked in March or April and held untU July. The new growth of the second 

 year has begim, but is somewhat irregular. 



Fig. 6.— Fry from Hope Island, Puget Soimd. May 28, 1915. Male, 94 mm. 



Fig. 7. — Yearling from same collection as figtire 6. Male, 97 mm. 



Fig. 8. — Yoimg chinook taken in Half Moon Bay, Calif. 



