MILKER FISHERIES OF THE GREAT LAKES. 75 



argentcus Kirt., wliicli is foimd very freiiiiently attached to t!ic skin. The 

 circiUar scars and raw sores sometimes fouud upon the sturgeon, and 

 attributed to this cause by the fishermen, are correctly accounted for in 

 this way. It is probable that their natural food is the slime or mucus 

 exuded iu abundance from the pores, but they fequently retain their hold 

 upon a spot until they have eaten through to the flesh, and deep ulcer 

 ous cavities occasionally result from the sore. 



The decrease iu numbers is apparent, to a certain extent, in localities 

 where the pound-net has been in use for a number of years. At San- 

 dusky, Ohio, the numbers brought in from the nets and handled at 

 tiie curing-establishment in a season are said to have nearly reached 

 eigliteen thousand a few years ago, while in 1872 the books showed a 

 record of thirteen thousand eight hundred and eighty received. This 

 fact has several times been advanced as an argument in favor of the 

 l^ound-net, that the destruction of the sturgeon, asserted to be an ex- 

 tensive spawn-eater, more than compensated for the numbers of white- 

 lish taken. 



25. — An important species. 



There is another species of fish, the walleyed pike, Stizostedion 

 amencana, a knowledge of whose habits would be important to a proper 

 conservation of the species, but its spawning season is in the spring and 

 earlier than circumstances have permitted us to visit its localities. 



