512 NATURAL HISTORY OF AQUATIC ANIMALS. 



their habits in this particular, inetal tags, with numbers indicating the locality, were distributed 

 to fishermen at twenty points along the lake, to be fastened to the fins of live fish, which were 

 then to be released. Instructions were at the same time sent to all fishermen to report the capture 

 of fish bearing these marks, and the distances from where they were taken to the point of departure 

 would indicate the extent of their migrations. It is thought that but few of them were, used. A 

 similar proceeding was afterward carried out by Mr. George Clark, of Ecorse, on the Detroit 

 River, but none of the fish were ever heard from. 



"Some of the fishermen of the west shore assert that, after severe storms encroaching on the 

 shore, and making the water muddy for a long distance out, when the storm subsides there is a 

 heavy deposit of mud on the bottom, and that the White-fish abandon the locality for a time, 

 because, as they surmise, their food is buried in the sediment. On the contrary, after ordinary 

 storms, there is generally an improvement in the catch of fish, probably for the reason that the 

 great aeration of the water renders them lively and incites them to move about. The migration 

 from the southern portion of Lake Michigan is of yearly occurrence, about the middle of June, and 

 is, without doubt, occasioned by the large extent of shoal water becoming heated. The same thing 

 occurs in Green Bay, and in the shoal regions of the western end of Lake Erie. The migrations 

 into shallow water, and up certain streams, in the fall of the year, for the purpose of spawning, 

 will be considered further on. This migration, and the summer visit to the shore, are the general 

 migrations peculiar to the White-fish, while the departure from shoal regions in summer, and from 

 certain localities in August, are local peculiarities." 



ENEMIES. This section of the natural history has been fully worked up by Mr. Milner in his 

 "Report on the Fishes of the Great Lakes," from which the following extracts are made: 



"The largest percentage of destruction the White-fish suffers is without doubt in the ova 

 stage. The spawn-eaters of the Lakes are a numerous and widely distributed list of animals, 

 including fishes, amphibians, and, it is claimed, divers and ducks. The destruction of the spawn 

 by these iiiethods is immense, and far exceeds the losses while in the stage of fry. The most 

 wholesale, devourer of the eggs is undoubtedly the Lake Herring. On opening the stomachs of 

 the Herring from the ponds in Detroit River, in November, they were found to contain the eggs of 

 White fish. At first it was considered possible that, as they were confined in the ponds, their 

 eating spawn might be a matter of necessity; but later, at Sandusky, their stomachs were found 

 gorged with the ova. The Herring, the most numerous species inhabiting the spawning grounds 

 of the White-fish, are without doubt the principal agents in keeping in check the increasing 

 numbers supplied from the fertilized ova. The suckers, sturgeon, and smaller bottom-feeding 

 fishes are found with spawn in the stomach. 



"The so-called 'water-lizard,' Menobranchiis lateralis, Say, is very numerous in some of the 

 streams and portions of the lake shore. Mr. George Clark, of Ecorse, Michigan, had a minuow- 

 soinc fitted to the bag of a sweep-seine, and at one haul took two thousa'nd of the 'water-lizards.' 

 Estimating the extent that the net had passed over, he calculated the average number of lizards 

 to each square rod to be four. He says, further, in one of the Detroit papers, 'The lizards were 

 so gorged with White-fish spawn that when they were thrown on the shore hundreds of eggs 

 would fly out of their mouths. . . . Some of the larger lizards would devour the whole spawn- 

 ing of a White-fish in a day or two; and when we consider that these reptiles are feeding upon 

 c.ugs from November till April, some idea may be formed of their vast capacity lor destruction.' 



"Mr. Browne, of Grand Haven, Michigan, states that some three years ago an epidemic 

 seemed to prevail among flic McnobranuM in Grand River in the month of June, and that their 

 dead carcasses wore washed ashore by hundreds, so that they lined the banks of the river, and 



