344 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



We have three spawn houses, or rather one developing house (exclu- 

 sively so) and two batching houses. The developing house is fed with 

 lake water. Its location compels us to vacate it in March, but the long 

 stay of the eggs in the cold lake water keeps development back, so that 

 none are hatched and grown enougli for planting untilJune, when their 

 natui-al food has become abundant. 



Our best hatching house stands on the lake shore and is a very sub- 

 stantial structure, partly under ground, with massive stonewalls; it has 

 capacity for developing 4,000,000 eggs or hatching 1,000,000. Troughs 

 are arranged on six floors, and water runs through the series, so that it 

 can be used at least three times, with ample facilities for aeration. We 

 pass water from one trough to another by letting it fall in a broad, thin 

 sheet over the side of the trough. This is very effectual, and young 

 hatched in this house are exceedingly vigorous. The above hatching 

 house covers 1,500 square feet of ground. We have also a neat little 

 cottage for the superintendent, a lodge for the foreman, an ice house, 

 and a wood-house, all in convenient proximity. 



Our method of manipulating fish is perhaps common. We use the 

 "dry method" wholly. Ten-quart tin milk-pans receive the spawn and 

 milt. The fish are used just as the "dipper" hands them up, male or 

 female first, as may chance. After the eggs of four or five fish are taken 

 and well milted another hand takes them, agitates them diligently for a 

 few minutes, and then washes them off at once, after which they stand in 

 pans on shelves till it is convenient to carry them to the hatching house. 

 Careful observation has shown that impregnation is instantaneous upon 

 contact of milt, and all agitation and waiting is merely to secure contact. 

 Milt in pure water loses spawn in a few seconds, retaining scarcely any 

 power after one minute. Eggs likewise soon lose their capacity lor im- 

 pregnation if put into water ; but a little water does no appreciable harm 

 within a few minutes. Either eggs or milt can be exposed to air for 

 hours without losing power. The mucus that comes with the eggs from 

 the fish does not act on milt or eggs like i)ure water; milt in it retains 

 its power for hours. If males are scarce we strain out the milted liquid 

 irom a spawn pan and use it again. In a can standing in water I have 

 kept it forty-eight hours and then used this mixed mucus and milt 

 effectively. 



Three-quarters of our eggs are shii)ped away. The owners are Maine, 

 Massachusetts, Connecticut, and the United States. We pack iusphag- 

 nous moss, wet to imbed the eggs, and dry to surround this mass. Sur- 

 rouuded by 3-inches dry moss they go on a sled, in the morning, with the 

 temperature 10 to 15 degrees below zero, 28 miles (taking the whole 

 forenoon), without the frost penetrating to them. The eggs are ready 

 to pack as soon as the eyes become black. We send all off' from Janu- 

 ary to March. What we keep hatcn in May and are set free in June. 



BucKSPORT, Me., February 15, 1883. 



