70 U. S. BUREAU OF FISHERIES. 



streams in the White Mountain National Forest, Such plants are 

 carefully handled under the direction of the forest supervisor. The 

 steelheads, the brown trout, and a small number of brook trout 

 remained on hand at the close of the year. 



HOLDEN (VT.) SUBSTATION. 



At the beo:inninn: of the year there were on hand upward of 

 100.000 fingerling fish of various species that entered into the dis- 

 tribution of tlie fiscal year 1922. The substation was supplied with 

 about 500,000 brook-trout eggs from the St. Johnsbury station. As 

 customary, cooperative work with the State of Vermont addressed 

 to tlie lake trout was undertaken at Lake Dunmore, resulting in the 

 collection of 323,000 eggs, which, together with 25,000 of the same 

 species shipped from Charlevoix, Mich., were incubated at the sta- 

 tion. Fish-cultural work at Lake Dunmore is showing very gratify- 

 ing returns. Each season a larger number of spawning fish are 

 available. 



The fish-cultural work at this substation during the fiscal year 

 1922 was unusually successful. All eggs handled produced a high 

 percentage of fry, and the mortality among all species during the 

 feeding period was light. In many seasons the mortality among 

 both eggs and fry held in the spring water has been high, and this 

 has been the subject of a number of investigations seeking the cause 

 and the remedial measures that should be applied. During 1921 a 

 new system of aeration was installed, which may have been an 

 important factor in the excellent results obtained during the fiscal 

 year 1922. 



YORK POND (N. H.) SUBSTATION, 



Actual fish-cultural operations at this point have been confined to 

 the rearing of fry transferred from St, Johnsbury, Vt., some experi- 

 ments in hatching brook-trout eggs in gravel, and the feeding of the 

 adult fish in the pond. The work accomplished toward the develop- 

 ment of the site for its ultimate object with the small amount of 

 funds available is gratifying and reflects credit on the superin- 

 tendent in charge of the work and his subordinates. The more 

 important structures completed during the year are the cement dam 

 diverting the water of Cold Brook to York Pond and a ditch carry- 

 ing this water across the crest of an intervening ridge. From the 

 ridge the water finds its way across a bottom of about 4 acres into 

 York Pond. Eventually this 4-acre bottom will be converted into 

 additional pond space. A control dam, also of cement, at the outlet 

 of York Pond permits control of the water level of the pond, and 

 one of the spillways in this dam has been continued to form a pit 

 for a Poncelet wheel, which will furnish power for a fish-food chop- 

 per, dynamo, and possibly a wood saw. 



During the winter after the work ceased a caretaker left in charge 

 of the property cleaned the underbrush from the margins of York 

 Pond, " slashed " two bottoms, which, with the completion of the 

 plans, will be flowed, and completed much other work of a similar 

 nature. In the course of the construction work a number of springs 

 have been uncovered. The flow from these when concentrated will 



