HISTORY OF THE PACIFIC SALMON. 603 



Humpbacks were first dealt with in the hatcheries in 1904, and 

 since then have been turned out from them intermittently, but 

 never in very large numbers, compai'atively speaking. 



They take their name fi'om a peculiar hump which appears 

 behind the heads of the males at spawning time. They are from 

 3 to 11 lbs. in weight, and have very small scales. 



The main run is in Alaska. South of Puget Sound the 

 Humpback is almost unknown. In the Fraser River the runs 

 in the big Sockeye years and in the years next but one after them 

 are much larger than in the other years. The fish, however, 



Text-fig. 116. 



Scale of Humpback Salmon {O. fforbtischa), from Puget Sound. 

 (For vef'erence see text, p. 604.) 



seem to come in at various ages, so this state of afiairsj will 

 probably gradually right itself again if the netting is not too 

 severe. I am judging from possibly but a few specimens. A 

 large number of Humpback scales have been sent me, but, 

 unfortunately, with no further information than that they were 

 taken from Humpbacks in Puget Sound on their way to the 

 Fraser River. I append a photograph (text-fig. 116) of one of 

 these scales. The centre is only moderately well defined, but in 

 all the othei's it is even less clear, so that I have not been able to 



