202 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



Two copious springs, recognized after many experiments as most favor- 

 able for hatching trout eggs, now furnish all the apparatus for fish -cult- 

 ure. The room used for hatching is about 56 feet long and 13 wide. 

 All around this are arranged in shelves cemented troughs, from 2 to 3J 

 feet wide. A lodging for the janitor extends from the building. 



Some indispensable covered reservoirs, with an area of about 65 square 

 yards, communicate with the hatching room. In front of this building 

 there has been dug a basin, with an area of 144 square yards, divided 

 into four compartments. The level of the water is regulated from the 

 inside. The different compartments are filled or emptied separately 

 with great rapidity, so as to capture easily the spawning fish. Being 

 fed from abundant springs, this basin never freezes. A boundary-wail 

 adjoining the buildings shelters it from all danger. All these reser- 

 voirs are intended to receive trout at spawning time. 



Taking trout for market begins about April 1, and ends about October 

 1 ; and about October 15 they begin to collect the eggs. At this time 

 the fish are taken either by the aid of ditches, spoken of by Raveret- 

 Wattel in a report on foreign fish-culture,* or with nets. In 1882, from 

 October 20 to November 15, there were taken 500 trout, one-fourth of 

 them females, which yielded 1 20,000 impregnated eggs. In 1883, during 

 the same time, 1 ,500 trout were taken, one-third females, and 330,000 eggs 

 were obtained. Of these 1,500 fish, 112 died in consequence of the ex- 

 traction of the eggs or from hurts received from the nets, the rest being 

 put back iu the lake. From these figures we can judge of the number 

 of trout necessary in order to obtain a large number of eggs. Notice 

 here that many females are either infertile or seem not to spawn every 

 year. It seems also that trout raised in captivity are too often infer- 

 tile or slow in breeding. 



Do not these considerations support this opinion, that a great fish- 

 cultural establishment can exist only on the border of a lake % Such 

 establishments can succeed everywhere where there are trout and 

 spring water; but so far as the reservoirs are only small bodies of water 

 or basins, they will produce only limited numbers of eggs. 



In 1884 they hope to obtain 1,000,000 eggs at Saint-Front. The 

 grounds, reservoirs, nets, &c, are sufficient for this ; 100,000 eggs will 

 be kept for the lake; the other 900,000 will be sold. There is no trouble 

 here about getting trout enough from which to obtain the eggs. On 

 November 20, 1883, the fishing of a single morning gave 118 trout, 

 weighing about 100 pounds. The supply of the eggs will then be limited 

 only by the demand. It will be sufficient to begin fishing for these eggs 

 some days earlier, or at the time of the last forwarding of trout to the 

 provision dealers, to save out the females and place them in the basins 

 at the time of spawning. The establish meut will then be able to respond 

 fully and satisfactorily to all the demands for eggs which may be made 

 upon it. 



* Bulletin de la Soci6l4 d 1 Acclimatation, November, 1883, p. 638. 



