524 NATURAL HISTORY OF AQUATIC ANIMALS. 



"A more successful series of tests were begun in 1868 by Seth Green and Samuel Wilmot in 

 applying artificial culture to this species, and in the succeeding year by Mr. N. W. Clark, of 

 Clarkston, Michigan. They were found to be very delicate and difficult to hatch in the first few 

 years of experimenting, but methods were perfected that made their production as certain and 

 with losses nearly as small as in other species. The necessity of production of immense numbers 

 in attempting to multiply the market species of fishes established the fact that the apparatus used 

 in trout-hatching had to be extended over a wide area to accommodate them. The culture of the 

 White-fish and the Salmon Trout induced modifications of apparatus at the New York State hatch- 

 ing establishment."" 



On page 548 of the same report Mr. Milner continues his observations: 



"A few extracts from a letter of Mr. Clark, to the board of fish commissioners of the State of 

 Michigan, will advance his arguments in favor of brook or surface waters in preference to spring 

 water. Mr. Clark began his experiments with White-fish in 1869, hatching a small percentage of 

 the eggs he procured : 



"'In November, 1870, 1 started again for Bcorse for the purpose of procuring more spawn. 

 Mr. George Clark, at his fishery, very kindly rendered me all the aid in his power, furnishing the 

 parent fish for the purpose of trying further experiments in this new enterprise. I succeeded in 

 obtaining all the spawn needed for further trial, but he was so anxious to make it a success that 

 he sent his man to me with an extra lot which he thought might be in better condition. I 

 succeeded in hatching a much larger proportion of them than the year before, but raising them 

 with artificial food was attended with no better success. This second effort and failure led me to 

 investigate the cause, and after much thought I came to the conclusion that, if we ever succeeded 

 in making this branch of pisciculture a success, we must study the principles of nature more than 

 had ever been done before. I became fully satisfied that by arranging so as to use water taken 

 from a pond or lake entirely frozen over, it would retard the development of the eggs to the time 

 required by nature, which proved by subsequent experience to be about April 1. I then consulted 

 Messrs. George Clark and John P. Clark, and made known to them my convictions, and so strongly 

 were they convinced that I had struck the key-note to insure ultimate success that they proposed 

 to furnish all the necessary materials and a portion of the labor to enable me to go on and erect 

 a large hatching establishment. This was located about eighty rods below the spring where we 

 had been experimenting the two years previous with the unsatisfactory results above stated. 

 This location was supposed to be a sufficient distance below the main spring, so that by damming 

 the water and raising a pond it would freeze over and remain so during the period of incubation. 

 Our views proved to be correct, as the 500,000 of eggs which we placed in the hatching boxes 

 November 15 of that year were preserved in fair condition, and with one-quarter less labor in 

 caring for them than formerly. They did not commence to hatch until April 1, and it was estimated 

 that we succeeded in hatching at least fifty per cent, of the eggs we had taken four and one-half 

 months previously at the fishery of George Clark. Of these young fry, seme 100,000 of them 

 were put in Detroit River, at or near his fishery place, and no doubt at this time they are thriving 

 finely in the waters of Lake Erie, which abounds with abundant natural food for them, and in a 

 year or two more they will doubtless return to the same place where they were deposited. The 

 balance of them we placed in three small lakes in Oakland County, some of which have been 

 seen within the last few months, doing finely. 



" ' This experiment proved so great a success that again, the next November, 1872, through 



1 Milner in Eeport of Commissioner of Fish and FisheTies, Part II, p. 545. 



