282 Roosevelt Wild Life Bulletin 



planting of 5,000 fry, providing it is possible to distribute the fry 

 in the headwaters of spring rivulets tributary to the stream which 

 it is desired to stock. Spring rivulets may be found tributary to 

 nearly all good trout streams. They may vary in length from one 

 or two miles to a few feet. In width they may vary from six 

 inches to two feet, and in depth from one to six inches. The 

 number of fry to be planted in such rivulets depends very 

 materially upon the length of the stream, and the prevailing 

 abundance of food. Few persons have opportunities to study the 

 food conditions, and it is accordingly safe to generalize by the 

 allotment of 5,000 fry to each mile of spring rivulet, with the 

 understanding that special care will be taken to scatter the fry the 

 entire length of the rivulet by planting a few at frequent intervals 

 with a dipper. 



" There is an important argument in favor of planting fry, 

 namely, the instinct of self-preservation, which is developed better 

 and sooner at the time of sac absorption, when the fry instinctively 

 seek natural food. The planting of fingerlings late in autumn, 

 when the water is very cold, is to be discouraged, for the reason 

 that after being trained to receive artificial food several times daily 

 for a period of several months, if planted in these cold waters, which 

 are almost devoid of food, fish which have been accustomed to seek 

 food under natural conditions become weakened from starvation 

 and are an easy prey to any fish of larger growth inhabiting the 

 same waters. 



" Small fingerlings properly planted the latter part of May or 

 during the month of June, reach the waters it is planned to stock 

 .at a period of the year when there is far greater abundance of 

 minute animal life. The natural food upon which they feed then 

 exists in greater abundance than later in the season, when the 

 larger fingerlings are planted. The results obtained from planting 

 twice the number of two-inch fingerlings than can be furnished of 

 four-inch fingerlings two or three months later will accordingly be 

 in favor of the two-inch fish." 



Some fish culturists also regard it as more economical to plant fry 

 than to raise the fish to a larger size. This may be true so far 

 as the immediate pecuniary considerations are concerned. But if an 

 undue proportion of the fry perish after planting, the apparent 

 saving in immediate outlay of money is a delusion, for the opera- 

 tion in an efifort to perpetuate the stock by planting large numbers 

 in any waters, in the long run is costing far more than is saved 

 by the actual lessened expense of planting at the fry stage. 



" The chief argument against planting of fry that has been 

 ofifered is that they are less able to withstand unfavorable conditions 

 than are fingerlings, and many applicants for fish have not been 

 trained to give the planting the attention which it requires. The 

 Commission is accordingly devoting much attention to systematic 

 educational work among the applicants with a view to better planting, 

 and meanwhile is continuing its eflforts to increase the output of 

 fingerlings." (Loc. cit.) 



