A METHOD OF CULTIVATING TROUTS AND SALMONS. 787 



their nests, about April 5. The run was then cleared of all fish, the water partly 

 shut off, and screens placed at each end to exclude fish and destructive animals. 



COMPARATIVE RESULTS. 



About April 20 fry first appeared in the race, and fine screens were placed 

 to prevent their escape into the ponds or out at the inflow. Two pools had been 

 prepared for them and these were now connected with the race. By June i 

 between 2,000 and 3,000 fry had hatched in the race, and these were about 

 equally distributed in the race and the two pools. At the present writing (August 

 10, 1908) less than a dozen of the fry have died from any cause, and several of 

 these perished by being caught in the screens. The fry now average nearly three 

 months of age and are in thrifty condition, with no evidence of weakness among 

 them. 



Not above twelve pairs of the fish spawned in the race, and several of these 

 were small females which were seen upon the nests but a few times, while the 

 larger fish occupied the nests at intervals during six to eight weeks. It is to be 

 considered that trout deposit but few eggs at a time, and this would appear to 

 be a strong argument against the stripping process. 



The fry appeared in the race, by careful count and removal, as follows: 



April 20 12 



April 22 8 



April 23 8 



April 24 4 



April 25 10 



April 26 10 



April 27 18 



April 29 II 



Thereafter, until late in June, from 20 to 50 fry appeared daily, and the 

 number then decreased until all had hatched. This may or may not be approxi- 

 mately the ratio in which the eggs were deposited, but it must be of value as 

 proof that they are deposited but few at a time, and covering considerable time. 



More than half of the spawners were kept out of the race by the pugnacious 

 males, or elected to spawn in the ponds. Some of these were the larger fish and 

 continued spawning throughout the season. Smaller fish, spawn-eaters, were 

 continuously raiding the nests in the shallows of the ponds. Only about 20 fry 

 appeared during the hatching season, and a dozen of these were saved by being 

 dipped out with a net and placed in the fry pools. None of the others survived. 



In conclusion, I desire to submit that these experiments, entailing much 

 labor and time, and observations made under very favorable conditions and 

 carefully recorded, have convinced me that it is not practicable to propagate 

 trout in limited areas of inclosed water, without provision for the protection of 

 both the spawning beds and embryos, and also the segregation of the fry until 

 they are at least six months of age. 



I do not beheve a simpler, more practicable, or economical method can be 

 devised to meet these requirements than the provision of adequate runs or races, 

 together with nursery pools for the fry, substantially as outlined in this paper. 



