THE SALMON FAMILY. 41 



spawning season of the white-fish the lake herring 

 feeds on the ova of the latter, thereby doing a 

 great amount of mischief. As food, this species is 

 fair, but much inferior to the white-fish. Its geo- 

 graphical distribution is essentially the same, but 

 to a greater degree it frequents shoal waters. In 

 the small lakes around Lake Michigan, in Indiana 

 and Wisconsin (Tippecanoe, Geneva, Oconomo- 

 woc, etc.), the cisco has long been established; 

 and in these waters its habits have undergone 

 some change, as has also its external appearance. 

 These lake ciscoes remain for most of the year in 

 the depths of the lake, coming to the surface only 

 in search of certain insects, and to shallow water 

 only in the spawning season. This periodical dis- 

 appearance of the cisco has led to much foolish 

 discussion as to the probability of their returning 

 by an underground passage to Lake Michigan 

 during the periods of their absence. One author, 

 confounding " cisco " with " siscowet," has assumed 

 that this underground passage leads to Lake Su- 

 perior, and that the cisco is identical with the 

 fat lake trout which bears the latter name. The 

 name " lake herring " alludes to the superficial 

 resemblance which this species possesses to the 

 marine herring, a fish of quite a different family. 



Closely allied to the lake herring is the Blue-fin 

 of Lake Michigan and of certain lakes in New 

 York {Coregonus nigripinnis) , a fine large species 

 inhabiting deep waters, and recognizable by the 

 blue-black color of its lower fins. In Alaska and 

 Siberia are still other species of the cisco type 

 (Coregonus laurettcz, C. merki, C. nelsoni) ; and in 



