172 POPULAR SCIENCE MONTHLY. 



rivers as the Skaguay Eiver, or they may be little brooks, in any case not 

 frequented by the king salmon, and having no lake in the course, 

 hence not fit for the red salmon. Their runs are confined to the 

 ignoble species, which ascend for a short distance only. In the larger 

 streams to the northward as Skaguay Eiver and Dyea Eiver, the dog 

 salmon predominates. Southward as in Fish Creek, at Ketchikan 

 and Anan Creek, the humpback salmon predominates, although the 

 humpback is equally common in the red salmon streams. Some of 

 these streams of the third class as Fish Creek flow through lakes. 

 Presumably these lack fit spawning grounds. 



The question as to what constitutes the mouth of the river is one 

 of some importance in Alaska. The tides run very high, often twenty- 

 five feet or more, the high tide extending far up the estuaries, which at 

 low tide may be occupied by fresh water. The Naha Stream at Loring 

 flows through a series of lakes, the lowermost of which (Eoosevelt 

 Lagoon) lies close to the estuary of the stream, the water flowing from 

 the lake over a considerable waterfall at low water. At high tide 

 this cascade is reversed, the salt water passes by an overfall into the 

 lake, which is thus converted into a brackish lagoon. It is a well 

 separated lake at low water, part of the sea at high water. 



