FISHERIES OF AMERICA 157 



We may conclude that its only object 

 in entering the rivers is to give its eggs 

 more protection than would be afforded 

 by a seabed filled with demersal fish. 

 The fish begin to run up the rivers in 

 June, when rapids, waterfalls, and other 

 obstacles are overcome : it is interesting 

 to watch the fish ascending artificial stair- 

 cases erected by the fishermen. The eggs 

 are laid in autumn, when the fish selects 

 a bed of clean gravel where the current 

 brings a constant supply of oxygen. A 

 trough is hollowed out of the gravelly bed 

 by several quick movements of the fish's 

 tail. The eggs are left in this hollow to be 

 fertilized by the male fish ; and they soon 

 become covered up with sand and gravel, 

 otherwise they would soon disappear into 

 the stomachs of trout or other predatory 

 fish. In a year when the numbers of 

 breeding fish were somewhat reduced the 

 fishermen continued to catch the usual 

 quantities. Still fewer, therefore, escaped 

 to breed, and, of course, there was a still 

 smaller quantity of that year's progeny 

 to return after four years. Thus auto- 

 matically, unless the State legislates to 



