MILNER FISHERIES OF THE GREAT LAKES. 41 



that are taken in any numbers are fifteen to eighteen inches in length, 

 and these are not very nunieroas. 



The average weight of tlie lake-trout taken in the gill-nets is nearly 

 five pounds. It is claimed that in years past they averaged much 

 higher. They are quite frequently taken weighing fifteen i)ounds. A 

 specimen of a female was obtained last summer at Shoal Island, Lake 

 Superior, weighing twenty-four pounds. One taken at Grand Haven, 

 Mich., in the month of Jiuie, 1871, a female, weighed thirty-six ijounds 

 and one-half. After the gills and entrails were removed, it weighed 

 twenty-nine pounds. It measured three feet six and one-half inches 

 in length. 



The tradition of the largest trout taken is preserved at each locality, 

 ranging from fifty to ninety pounds. One that I am satisfied was au- 

 thentic, from having taken the testimony of those who saw it weighed, 

 and having the story confirmed by Father Peret, of Mackinaw, was 

 taken at that place in 1870, and weighed eighty pounds. 



There are no species of fishes in the lakes sufficiently formidable to be 

 considered enemies of the trout after they mature. The spawn and fry 

 probably suffer to some extent from the same causes that the ova and 

 young white-fish do. 



They are troubled with a few parasites, especially a tape- worm that 

 is found very numerous in the intestines of some of them. Solitary in- 

 dividuals, known among the fishermen as "racers," are found in the 

 summer-time swimming sluggishly at the surface. They are easily 

 taken with the gaff-hook, and bite readily at any bait thrown to them. 

 They are always very thin in flesh. Dissection of the few that I have 

 taken failed to find any adequate cause for their condition. The para- 

 sites were generally i^resent, but not in any larger number than in 

 healthy fish. 



The fishermen on the north shore of Lake Michigan generally keep 

 a few hogs. The oftal of the white-fish is fed to them freely, but they 

 are very careful to allow no trout-offal to be thrown in their way, as- 

 serting that the hogs, after eating trout, frequently become crazy and 

 die. The only i)lausible explanation of this fact, if it is a fact, is that 

 some entozoon of the Mackinaw trout, passes through one stage of its 

 development in the hog, and occasions disturbance of the brain, having 

 much the same habit as the cystic Coenuriis does in the sheep. 



Dr. Bannister informs me that the opinion prevailed amojig some of the 

 Russian residents of Alaska that a tape-worm was occasionally pro- 

 duced in tlie human subject by eating the chaiwicha, Salmo orientaUs 

 Pal., the largest species of salmon common in that country. The fact 

 that it was quite a common practice to eat fish frozen, or dried, or salted, 

 without cooking, would favor the introduction of any parasite existing 

 in the body of the fish. 



The decrease in lake-trout is not so apparent as it js in the white-fish. 

 The pound-nets have not made the extensive inroads upon their numbers, 



