PROPAGATION AND DISTRIBUTION OF FOOD FISHES, 1923. 71 



department were engao^ed in cooperative work in the collection of 

 lake-trout eggs in Lake Dimniore. The returns from this work were 

 the largest ever secured, the total collections amounting to 684,020 

 eggs, of which 580,600. or nearly 85 per cent, were eyed. Fifty 

 thousand of the bureau's half of this stoc-k were retained at the 

 Holden station for development, and the remainder was forwarded 

 to the St. Johrsbury station. Brook-trout eggs to the number of 

 250,000. purchased from a commercial fish-culturist and delivered in 

 January, were held in brook Avater with a small admixture of spring 

 water to keep them from freezing. From this consignment 238,400 

 healthy fry were hatched and distributed. 



YORK POND (N. H.) SUBSTATION. 



During the summer months a large amount of work was done at this 

 substation in the way of improvements to the proposed pond system, 

 with the view of developing it at the earliest possible date into a 

 source of supply for brook-trout eggs for stocking various hatch- 

 eries of the bureau. 



Diverting ditch Xo. 1 was continued along the south side and 

 over the point of the separating ridge and then dropped into jpond 

 B. It is the intention to pass this water from pond B into the 

 spawning race at the head of the main pond. In preparation for 

 the coming spawning season, a raceway of planks. 6 feet 2 inches 

 Avide and extending 110 feet into the main pond, was provided for 

 conducting water from pond A, a temporary diverting dike having 

 been erected on the natural outlet to throw the water through the 

 raceway. TAvelve-inch drain tiling was laid from the kettle of pond 

 A to York Pond, and 350 feet of cast-iron pipe, leading from the 

 main lake to the hatchery, was installed. Races Nos. 1 and 2 were 

 put in shape for rearing operations; the sidetrack grade, running up 

 Cold Brook, was cleared and Avork started on a third rearing race, 

 which, like all the others, Avill have spring Avater rising copiously 

 in it. augmented by water from race No. 1, independent springs, 

 and Avells, and water diverted from Cold Brook. Below this race 

 there is opportunity for the construction of a number of ponds, the 

 How from which will be to the hatchery flat, where there is space for 

 further pond construction. A fourth raceway has been started along 

 the hillside west of the hatchery flat, and this Avill later be extended 

 some distance west of Cold Brook. 



During the summer months fishermen were employed to catch 

 trout in the closed brooks. These streams are so filled Avith drift- 

 wood and brush that no other practicable method has jet been de- 

 vised for taking them, and it was found that by filing off the barbs 

 of rather large hooks the fish are not apt to undergo material injury. 

 Of 1,964 captured in this manner only 12 had be^n lost at the end 

 of the season. The fish were held in a large inclosure prepared 

 for them on the natural inlet and fed until spawning time, when 

 an examination disclosed that only 254 were mature females. These 

 fish were so small that only 42.450 eggs were secured, and to supple- 

 ment the supply 100,000 brook-trout eggs and 25,000 lake-trout eggs 

 were forAvarded frorn the St. Johnsbury station. 



It having become evident that the cement hatchery and pipe line 

 from York Pond could not be completed in time to care for the eggs, 



