MILNER FISHERIES OF THE GREAT LAKES. G3 



books set iu the lake, and in one day took from these five hundred lizards, 

 removing- them all himself, as his men, sharing tlie popular notion on the 

 lakes, believed them to be poisonous, and preferred to cut away hook 

 and all to taking hold of the slimy amphibian. They are, of course, en- 

 tirely harmless in this particular, and make no more attempt to bite than 

 a frog" does. . 



A full series of this species was this season collected from Detroit 

 Eiver, from the length of one and one-fourth inches to thirteen inches. 

 Later, about the middle of the month of July, Mr, George Clark col- 

 lected a quantity of their eggs, proving- this month to be the spawning- 

 season of the animal. 



The sturgeon are very generally believed to be spawn-eaters. Though 

 the ova of the white-lish and the perch have been observed among the 

 stomach-contents of this fish, the principal food has always been found 

 to be snails, the fresh-water genera being generally represented, the 

 weaker shells crushed into fragments, and the stronger ones of the Fa- 

 liidinidcc and even Limneas remainiug unbroken. 



Dr. E. Sterling, of Cleveland, who examined the stomachs of a large 

 number of sturgeon in the vicinity of the Sandusky fisheries, made the 

 same observation. 



There are few of the bottom-feeding fishes but whose stomachs will 

 not generally be found to contain a few eggs, though in company with 

 other food in greater quantity. 



The white-fish stomach is generally found to contain a few fish-eggs, 

 though its principal food is the Crustacea. The habit of leaving the shore 

 immediately after spa^raing probably prevents it from being an agent in 

 diminishing its own numbers. 



The natural casualties of storms, deposits of sediment, smothering the 

 eggs, the vegetable growth Ibund to be so fatal in the hatching-troughs, 

 are to be considered iu this oounection as the dangers, though more fully 

 represented on another page. 



In the fry-stage they must suffer to some extent from the piscivorous 

 fishes. The most numerous and voracious of their enemies is likely to be 

 the wall-ej^ed pike, Stizostedion amcricaua, numerous in the shoal waters 

 of the lakes and comparatively rare on the deeper shores. The perch, 

 Percaflavescens, are very generally distributed and quite numerous; the 

 contents of their stomachs are generally found to be vertebrate forms. 

 The black-bass, Micropterus nigricans^i^ plentiful in Lake Erie, but as its 

 ordinary food is the craw-fish, where these are numerous its depredations 

 on the schools of young fish w^ould be of comparatively little importance. 

 The white-bass, Boccus chryso2)S, the muskellunge, Esox nohilior, and the 

 lake-pike, Esox Indus, do not inhabit the lakes in sufiicient numbers to 

 be very troublesome to the white-fishes. 



It is the prevailing idea on the lakes that the Mackinaw or salmon- 

 trout feeds largely on the white-fish. This point has been fully consid- 

 ered on a previous page, and the evidences disproving it related. 



