THE SACRAMENTO SALMON. 199 



Compare this table with the one showing the effect of pure water on 

 the ova. Acting upon the information gained in this experiment, we 

 removed the imspawned ova from the fishes, washed off the blood with 

 normal salt solution, and fertilized them just as we did other ova, thus 

 saving a large percentage that had previously been lost. 



Habits of the Young. 

 Before this series of investigations was begun, fish culturists were 

 able to hatch artificially from 80 to 90 per cent, of the eggs taken, and 

 it did not seem that much improvement in that line was probable. But 

 there was considerable question as to the best methods of planting the 

 young. We were entirely ignorant concerning the life of the young 

 in the streams, knew nothing of their food, nor of their enemies, and 

 knew only in a general way that they migrate to salt water. Our most 

 important study, therefore, was that of the natural history of the 

 young, and later of the adult also. The following are some of the 

 results of our investigations: 



\ 



An Alevin. A Fry, at the beginning of the Migration. 



The time required for salmon eggs to hatch is about 50 days, though 

 it varies from one to six months, according to the temperature of the 

 water. When the young first leaves the shell, it is attached to a large 

 mass of yolk, and is known as an alevin. It is a very helpless creature, 

 cannot swim and fortunately does not need to eat, the yolk supplying the 

 needs of growth. 



For three or four weeks the alevin lies quietly at the bottom of the 

 stream in the crevices of the stones. By that time the quantity of the 

 yolk becomes so small that there is a desire for more food, and the 

 alevin occasionally leaves the bottom to snap at some floating particle. 

 It is at this time, while the movements are slow on account of the 

 unabsorbed yolk, that the young under natural conditions are in the 

 greatest danger from other fishes. In artificial propagation they are 

 protected during this period, and it is only after the complete absorp- 

 tion of the yolk that they are liberated in the streams. At this age they 

 are known as fry. 



The fry are practically without enemies. The stomachs of more 

 than a thousand trout taken in streams inhabited by young salmon 

 have been examined, but in no instance has a fry salmon been found, 

 though alevins were common enough. Many Sacramento pike and 

 striped bass have also been examined with a like result. There can be 



