XCII REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



vicinity that could be used, an awning of canvas was erected over the 

 troughs. 



The work was successful, over 3,000,000 grayling eggs being collected 

 between May 7 and June 20. Of these, 1,500,000 were hatched at the 

 substation and deposited in Elk Creek, an inlet of Eed Kock Lake. Of 

 the balance, 1,000,000 were transferred to Bozeman and 110,000 were 

 shipped to other stations. 



The eggs of the grayling are much smaller than those of the trout 

 and measure one-seventh of an inch in diameter after fertilization. 

 They are very light-colored, almost crystal-clear, and are slightly adhe- 

 sive after fertilization, forming bunches and quickly developing fungus. 

 Their specific gravity was found to be less than that of trout eggs, and 

 from the experience gained it appears that they might be hatched or at 

 least eyed under pressure of water, by methods similar to those employed 

 in hatching eggs of the shad and whitefish, rather than on trays. The 

 embryo began to show life and movement before the appearance of the 

 eye spot, which occurs in from 3 to 5 days. They hatch in from 10 to 

 12 days at a temperature of 50°. The fry are quite small, about half 

 an inch long, and after the absorption of the yolk-sac, which requires 

 about a week, they rise to the surface and swim freely. Considerable 

 difficulty was experienced in providing acceptable food for them, aud 

 the loss before they commenced feeding was estimated at 50 per cent. 

 Those hatched at the substation and planted in the creek from which 

 the eggs were taken seemed to grow much faster than those in the 

 hatchery. 



Notwithstanding the short period of incubation, little difficulty was 

 experienced in the transportation of eyed eggs. Tlie consignments sent 

 to Manchester, Leadville, aud Omaha arrived in good condition. They 

 were packed in the manner usual with trout eggs, except that no moss 

 was placed between the trays, as the least pressure on the eggs kills 

 the embryo. Most of the loss in shipments to Bozeman was caused by 

 the scarcity of ice at the auxiliary station. One shipment of green eggs 

 was made, but all of them died eventually, though they were apparently 

 in good condition on arrival. 



During the spring 100,000 brook-trout eggs and 50,000 steelhead eggs 

 were received from the Leadville and Fort Gaston stations, and from a 

 private hatchery at Hudson, Wis. These were hatched as usual and 

 held at the station until the close of the year, when there remained on 

 hand the following stock of fish : 



