FISHERIES, GAME AND FORESTS. 237 



ponds and the screens are closed leaving the naturally impregnated eggs to work out 

 their own salvation in the clean gravel. After the fry are hatched and the umbilical 

 sac with which they are born is absorbed and they are ready to feed, they are induced 

 to leave the gravel beds and find their way in the gentle current down on to the sand, 

 by lifting the doors in the roof and admitting the light from the ends. Once on the 

 sand, the dam formed by the upright planks prevents their return to the gravel ; and, 

 whenever it is deemed necessary, they may be moved with net and bucket to a rearing 

 pond outside to be fed until such time as they may be grown to a size suitable for 

 planting in fishing waters or reserved for breeding purposes. In the hatchery that is 

 illustrated, it is estimated that about 300 breeding fish are admitted to the house each 

 year, although the ponds from which they come contain thousands of trout. Those 

 that are denied the convenience of the hatchery spawn in the ponds, and the eggs and 

 fry must submit to risks and perils which abound in such places ; but I have been 

 surprised to find that so many fry as I have seen in the ponds in spring and summer 

 have survived the attentions of their parents and relatives. 



Nothing is said here about the cost of such a hatchery as is described, as the cost 

 will vary in different localities, depending upon nearness to lumber supply, and price 

 of labor, but with the general plan given in the plate, it will not be difficult to make 

 an estimate of the probable cost when the location is selected. Such a hatchery could 

 be adapted to other water supply than one coming in springs from the bottom, but 

 usually springs are to be found by searching the shores of trout waters, and such a 

 supply of water, with its even flow and temperature, is to be preferred to one coming 

 from a stream liable to floods, discoloration and impurities. 



About the only care such a hatchery requires is to rake over and scrub the gravel 

 of the beds after the fry is removed, and this is done by forking it up at the sides while 

 the water runs through it; for, while the gravel remains white and clean as long as the 

 doors remain closed and it is dark inside, the sunlight causes green "mold " (desmids, 

 representing a family of minute Algce) to form on the gravel, which should be brushed 

 off with a broom and dead eggs washed out at the same time. Such a hatchery will 

 require but little of one man's attention for the most part, and the returns from it 

 abundantly repay the outlay for construction. There is no way to count fry in such a 

 hatchery until they are netted out to be placed in an outside rearing pond, but last spring 

 I estimated that the hatchery in the illustration contained 60,000 or 70,000 strong, 

 healthy fry, and it was believed that not many more than 300 trout were admitted to 

 spawn in it last fall. The club desires to rear only a certain number of trout each 

 year, to turn into the fishing pond something more than the number annually caught; 

 but in a preserve, for instance in the Adirondacks, it would probably be desired that 

 all the trout should be allowed to spawn under cover and so the hatchery would have 



