208 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



in the city of Paris, by whom attention was regularly given to the differ- 

 ent fishes which occupied the aquarium. 



Being liberally fed with the flesh offish minced fine, the young sal- 

 mon attained in the space of a year a mean weight of 250 grams. At 

 this period almost all had lost the markings of their early age, and had 

 taken on the beautiful silvery appearance of smolts ; but they did not 

 manifest that anxiety which is generally observed in our common sal- 

 mon of the same age when kept in captivity. They bore their confine- 

 ment perfectly well, and the losses were comparatively small. 



Two years later these salmon had become very fine fish. Some 

 weighed as much as 2 kilograms. In October, 1SS1, several of them 

 gave evident signs of maturity. Artificial impregnation was attempted ; 

 but the eggs obtained appeared badly developed and did not give any 

 result. Moreover, all, or almost all, both males and females, which had 

 appeared disposed to spawn, died. 



The following year, 1882, also in the month of October, the desire of 

 spawningmanifested itself anew in these fish, and on the 24th of October 

 several females yielded about 1,500 eggs, which we attempted to fecun- 

 date with the milt of the trout, because there were no ripe male salmon 

 at this time. The experiment did not succeed ; but a few days after- 

 ward, individuals of both sexes being in full spawning condition, there 

 were collected and fecundated in the space of five weeks about 30,000 

 eggs.* 



Unfortunately, the want of sufficient apparatus for hatching necessi- 

 tated the crowding of the eggs for several days in a very restricted 

 space. Moreover, the work of repairs in the water conduits which 

 supplied the aquarium permitted the use for some time of only unfil- 

 tered water. To these two causes is to be attributed the bad success 

 with a large number of the eggs, which from their fine appearance it is 

 thought should have almost all reached the period of hatching. 



About 1,500 very vigorous fry were, however, obtained, and are now 

 in perfect condition. This suffices to demonstrate the possibility of 

 rearing and of effecting the reproduction of the California salmon under 

 conditions of captivity entirely exceptional. This fact is the more in- 

 teresting as it relates to a foreign species essentially migratory, which 

 has been at the same time transported to a new climate and subjected 

 to a complete change in its habits. It seems, therefore, that we may 

 readily effect the acclimation of this species, and this is particularly 

 desirable with reference to the stocking of the water-courses tributary 

 to the Mediterranean, in which the ordinary salmon is unknown and 

 would not probably succeed. The California salmon extends in America 

 to the thirty-fifth degree of latitude, that is to say, much more to the 

 south than the Salmo salar, and could be undoubtedly acclimated in 

 the lihone, the Aude, the Ilerault, &c. 



"The individuals which spawned died at once. 



