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On July 24 four small Eedfish were caught on the net in Alturas inlet, and in 

 a day or two they were abundant in this stream. Evidently, therefore, they had 

 entered the lake at some date prior to July 20, and had remained in it until the 

 evening of July 23 when they first entered the inlet. 



Beginning with July 23 the fish continued to enter the inlet until early in 

 September. During this time at least 2,000 Eedfish, only about a dozen of which 

 were of the large form, entered this small creek. Hundreds of these were ex- 

 amined as they were running up into the inlet from the lake, and not one of them 

 showed any sores, frayed-out fins, or mutilations of any kind. Toward the close 

 of the spawning season there was scarcely a fish whose fins were not more or less 

 worn out (frequently the caudal was entirely gone) and whose back or sides were 

 not sore. And we were able to see how these mutilations were received. 



During the spawning period there is a rather definite pairing oflT of the sexes. 

 The spawning beds are usually in very shallow water on a bottom of fine 

 gravel and sand. While spawning, this gravel and sand is moved about a good 

 deal and made up into so-called nests, both sexes taking part in the work. The 

 gravel is moved about by the fish striking it with the tail, or by pushing against 

 it with the lower fins, or sometimes even with the dorsal fin and the back. The 

 gravel is moved by a rapid, quivering movement of the body as the fish swims 

 over the nest; then she circles around down stream a feAv feet and approaches the 

 nest to repeat the act again. The male follows closely behind the female, and 

 frequently moves the gravel in the same way. 



The fish move about to some extent in the inlet, but there is no evidence that 

 they ever try to return to the lake. Our nets caught a good many from the upper 

 side, but they were nearly all dead or dying fish which had been carried down 

 by the current, and were only slightly gilled or simply lodged against the upper 

 side of the net. We saw no evidence whatever indicating any tendency to return 

 down stream, and it is not easy to believe that any fish, so seriously mutilated as 

 these all are at the end of the spawning season, could survive. On September 5 we 

 counted about 1,000 fish in Alturas inlet ; two weeks later all had died but about 

 150, and a week later practically all had died. 



We consider it, therefore, absolutely proved that the Redfish which spawn in 

 the inlets of the Idaho lakes spawn only once and then die, and that the mutila- 

 tions are received on the spawning beds. 



