40 KEPORT OF COMMISSIONEE OF FISH AND FISHERIES. 



ample of the Mackiuaw trout and the white-iish. lu this trout the 

 very deepest tints fouud in the flesh of the sahnon are frequently to be 

 seen, while the food of the trout is almost wholly fishes, and in no case 

 crustaceans; while in the white-fish the flesh is of the purest white, 

 and the food is almost wholly crustaceans, and largely of Gammaridae^ 

 with a considerable amount of the red pigments referred to in their 

 shells. 



The spawning-season of the trout begins abojit a month earlier than 

 that of the white-fish. The details of their habits I can only give from 

 information I have gathered by continually questioning fishermen and 

 others who have had better opportunities of observing them than I 

 have. The universal testimony is that the spawn is found running from 

 the females in the latter part of the month of October, the fish coming 

 on to the spawning-ground a week or more earlier. 



At Detour, at the head of Lake Huron, on the IGth October, I saw a 

 large lift of trout brought in from the spawning-grounds; the ova were 

 large and separated, but were still entirely retained in the folds of the 

 ovaries, and the fishermen said they had not fouud them running from 

 this fish as yet. 



The localities selected by the trout for their spawning-ground are 

 usually rock bottoms in from fifteen fathoms to seven feet of depth. 

 Near Milwaukee, on a reef at about the greater depth named, is a spawn- 

 ing-ground, from which for years a large type of trout has been taken. 

 The spawning-grounds are found from Racine north on the western 

 shore of Lake Michigan, and from a little to the northward of Saint 

 Joseph north on the eastern shore. The spawning-ground nearest Saint 

 Joseph is said to be a clay bottom. At Detour the nets were set so 

 close to the shore that the tips of the floats showed above water. 



The trout are said to settle close to the projections and edges of the 

 honey-combed cavities of the rock, and that, frequently, when a loose 

 fragment of the rock is drawn up by the nets, the cells are fouud to 

 contain numbers of the eggs. w 



Theovaries from a Mackinaw trout of twenty-four pounds weight were 

 preserved, and weighed three pounds four and one-fourth ounces, and 

 contained fourteen thousand nine hundred and forty-three eggs; the 

 calculation being made by counting a fractional weight. 



The knowledge of the time at which the young fish make their appear- 

 ance is limited to the experience of the few fish-culturists in the country 

 who have hatched the eggs. In water of an average temperature of 

 47*^, they are found to hatch about the last week of January. At the 

 lower temperatures of the water, in a state of nature, their development 

 would be retarded for several weeks. 



Of the habits of the young trout 1 am entirely destitute of informa- 

 tion. I have seen one of eight inches in length, and learn of rare in- 

 stances in which the fishermen have seen small ones. The smallest ones 



