28 BULLETIN OF THE BUREAU OF FISHERIES. 



Table 22. — Young Chinooks from Clackamas Hatchery, Oreg., Dec. 4, 1914. 



Length. 



151 to 15s mm. 

 146 to 150 mm . 

 141 to 14s mm. 

 136 to 140 mm. 

 131 to 1.^5 mm. 

 126 to 130 mm. 

 121 to 125 mm. 

 116 to 120 mm. 

 Ill to IIS mm. 

 106 to no mm. 

 loi to 105 mm. 

 96 to 100 mm. . 

 91 to 95 mm. . . 



Total 



Av. 121. 1 mm . 



Number 



Total. 



With 

 check. 



Scale recoid. 



Average number of rings- 



To 

 check. 



6.0 

 8.0 



7-S 

 9-3 

 8-5 

 8.3 

 8.6 

 8.9 

 8.6 



To- 



Of- 



New growth. 



23.0 

 24- S 



2I'S 



22. o 

 20. I 

 20. 6 

 19.0 

 19.4 

 17-3 

 19-4 



17.0 



Average length of anterior 

 radius — 



To 



check. 



30.0 

 39.0 



28. o 

 28.0 

 28.0 

 25- S 

 21.0 

 24.2 

 23.0 

 iS.o 



24.8 



To new 

 growth. 



57- o 

 73.0 



65.5 

 68.0 

 57- o 

 SS-S 

 54.0 

 SS-S 

 43- o 

 48. o 



53- o 



Total. 



63. o 

 * 70.0 



81.0 

 70.0 



Average estimated 



length offish at time 



of formation of^ 



Check. 



67.0 

 SS-5 



60. s 

 54- S 

 56.0 

 48.0 

 SO.o 

 510 

 46.0 

 50.5 



4J.O 



New. 

 growth. 



127.0 

 127.0 



iis-o 

 no. o 



a The fact that this is less than the length to the beginning of the new growth is due to the fact that the specimen not having 

 the new growth had unusually large scales. 



All but nine of the specimens have winter rings at the margins of the scales. Of 

 these, four have a marginal band of wider rings, indicating that a period of more rapid 

 growth has begun. This is probably the new growth of the second year. The remain- 

 ing five specimens still show at the margins of the scales the wide rings of the first sum- 

 mer's growth. 



December 3 to 8, 191 5, several collections were made at different points on the 

 Columbia River between the mouth of the Willamette River and Astoria. Collecting 

 was rather difficult on account of inclement weather and unusually high water for this 

 time of year. Collections were made in the following places : Upper Willow Bar, Lower 

 Willow Bar, Deer Island, Mayger, Oreg., Wallace Island, and Seal Island. Unsuccessful 

 attempts to collect were also made at several other places. The collections are all quite 

 small, and the total number of fish taken was but 38. This represents the results of over 

 30 hauls with the lOO-foot seine. One of the specimens collected is a small fry only 

 35 mm. in length. This is obviously a fish of the year, and therefore one year younger 

 than the other individuals. No scales have been developed. This specimen is not in- 

 cluded with the older fish in the following table. Fourteen of the older specimens are 

 males averaging 95.5 mm. in length. Twenty-four females average 93.4 mm. The av- 

 erage length of all specimens is 94 mm. No significant differences have been observed 

 in the several collections, and they are therefore cast together in the following table (23) : 



Table 23. — Young CmNOOKS from Lower Columbia River, Dec. 3 To 8, 1915. 

 SEVENTEEN SPECIMENS WITHOUT INTERMEDIATE GROWTH. 



