18 DEVILS LAKE, NORTH DAKOTA. 



{Lotus atricilla) and common terns {Sterna hirundo) rear their 

 young on the rocky shores and islands of the lake and feed upon the 

 sticklebacks and minnows. A few great gray sea gulls {Larus 

 marinus) were observed associating with the black-headed form. 

 Flocks of black terns {Hydrocheilidon nigra) were not uncommon, 

 being generally seen flying over the marshes and weed-grown por- 

 tions of the lake. Along the shores many forms of sandpipers, kill- 

 deer, and allied forms were numerous, feeding on the exposed muddy 

 flats, and snipe were at all times abundant. Hell-divers, loons, and 

 ducks were everywhere to be seen. 



The flora of the lake is exceedingly scanty for reasons already in- 

 dicated. All or nearly all of the shallower waters contained a spe- 

 cies of waterweed {Ruppia maritima) . The shores are practically 

 devoid of vegetation, though wild flowers of the hardier northern 

 varieties flourish profusely on the prairies and pastures sloping 

 downward to the lake. 



Both the plankton and tow nets gave fruitful results. Towings 

 made along the shore and off the wharf of the Chautauqua grounds 

 revealed a remarkable supply of microscopic forms. Towings at and 

 below the surface of the water for periods of but one minute yielded 

 three liquid ounces, principally of copepods {Diaptomns pallidus). 

 A few small water bugs {Notonceta sp.) and amphipods occur. The 

 abundance of life varies, as is to be expected, throughout the lake 

 system, the weed-grown shallow portions of the shores and bays 

 yielding the richest returns. In the more protected w^aters of the 

 lake the minute life could be seen with the eye, darting among the 

 rank, coarse vegetation, literally by the millions. Vertical hauls were 

 made with the plankton net during the course of the hydrographic 

 work at stations in various portions of the lake, the stations being 

 located by the same methods employed for obtaining water speci- 

 mens. The results of all hauls proved satisfactory. 



The importance of these minute living organisms must be consid- 

 ered carefully in relation to the presence of minnows and stickle- 

 backs. The food of young fish in general includes insects — adults 

 and larvse — worms, mollusks, crustaceans, smaller fish, fish eggs, and 

 vegetable matter. The part that the plankton Crustacea play is im- 

 portant. 



DISAPPEARANCE OF PICKEREL. 



From all information available it appears that prior to 1889 Devils 

 Lake was well stocked with pickerel. This was, perhaps, an influen- 

 tial factor in the selection of a reservation on its shore by the Sioux 

 Indians, and also in the influx of peoples of Scandinavian origin. 



According to excellent authorities, these fish averaged from 5 to 6 

 pounds, a number of 17 or 18 pounds weight were caught, and one 



