232 TROUT AND SALMON 



September; those going to the Big Sandy in Oregon, in July 

 and early August; those going up the Snake to Salmon Falls, 

 in October; while those entering the lower tributaries of the 

 Columbia, or small coastal streams, spawn even as late as 

 December." 



''The spawning extends over several days, the eggs being 

 deposited upon beds of fine gravel, in clear, cold mountain 

 streams." The temperature of the water must be about 54°, 

 and if on arrival it is much above that, the fish wait until it 

 lowers. ("American Food and Game-Fishes.") 



A very remarkable feature about the spawning of the 

 salmon is that after it is completed both males and females 

 die! 'This," say Jordan and Evermann, "is true of all, 

 whether spawning remote from salt water, or only a few miles, 

 or yards, from the sea," and whatever the cause may be, it 

 "is general in its application to all the Pacific coast salmon." 



Inasmuch as the bodies of many dead salmon show injuries 

 of many kinds, the belief has become prevalent that the fish 

 injure themselves by striking against rocks on the run up- 

 stream, and ultimately die from wounds so received. But the 

 investigations of Drs. Jordan and Evermann have completely 

 disproved this. It was found that of the many salmon ex- 

 amined immediately after arrival on their spawning-grounds 

 in central Idaho, not one showed any bruises or mutilations, 

 and all were in excellent condition. The mutilations which 

 subsequently were observed were obtained either by righting, 

 or by pushing the gravel about on the spawning-beds. 



Salmon eggs hatch in about fifty days. During the first 

 six weeks the egg-sac supports the life of the alevin, which 



