MANUAL OF FISH-CULTUEE. 69 



over, tlie necessity of collecting breediug fish early in the summer does 

 not exist, because they are at no time more congregated and easy to 

 catch than at the spawning season. 



Their capture is easily effected by stretching a net across the outlet 

 of the lake and leading them through a tunnel-formed passage into an 

 inclosure of netting. There happens to be at this point a wide surface 

 of smooth bottom, with water from 1 to 3 feet in depth, affording an 

 excellent site for spacious inclosures, not only for entrapping but for 

 assorting and storing salmon during the spawning season. Xets are 

 generally stretched across the stream (to keep the fish back in the 

 lake) immediately after the beginning of the close season, September 15. 

 The earliest of them begin to spawn before the end of October, but the 

 actual inclosing of the breeding stock is deferred until the early days 

 of November. The taking of spawn generally begins about November 

 6 and continues two or three weeks. Commonly by iSTovember 20 or 22 

 this work is completed, and the breeders are carried a mile or two up 

 the lake and liberated. 



The method of manipulation is the same as at the Craig Brook station, 

 and does not differ materially from that adopted by all the American 

 breeders of Salmonidce. The results in the impregnation of the spawn 

 are not so uniformly satisfactory as with sea salmon. There appears 

 to be a greater prevalence of ovarian disease than among the migratory 

 salmon. The occurrence of white eggs among the normally colored 

 and healthy ones as they are yielded by the fish is very common, and 

 occasionally the entire litter is defective. It is not improbable that 

 some eggs are incapable of impregnation, though exhibiting no visible 

 signs of disease. However, the general result is satisfactory, the ratio 

 of impregnated eggs being from 93 to 95 per cent. 



The facilities for developing and hatching the eggs at Grand Lake 

 Stream are rather poor. No good site could be found by the side of 

 the stream, no suitable brook could be found near enough to the fishing- 

 grounds, and the neighboring springs lacked either volume or facilities 

 for utilization. Of three hatcheries, two use spring water exclusively, 

 and one of them lake or stream water exclusively. The lake water is 

 preferred, but unfortunately it can only be used for the slow develop- 

 ment of part of the eggs, circumstances connected with the floating of 

 timber down the stream compelling the evacuation of that hatchery in 

 March. The main hatchery is well located except that the water is from 

 springs, and this unfavorable circumstance is well counterbalanced by 

 the facilities for aeration, which are very good and very fully employed. 

 The eggs are placed upon wire-cloth trays in stacks or tiers, ten deep, 

 and arranged for a free horizontal movement in the water. 



The egg shipments are made in January, February, March, and some- 

 times in April. The eggs hatched are selected from those that have 

 been retarded in development; the fry reach the age for liberation in 

 June, when their natural food is believed to be abundant. 



