OPERATIONS IN CALIFORNIA IN 1873. 417 



losses was not to diminish the total number of eggs, but simply to make 

 us more work ; for the fact was that salmon-eggs were so abundant that 

 any loss could be replaced at once, and was actually so replaced as fast 

 as the loss occurred. By referring to the daily table of eggs taken, it 

 will be seen how easily this was done. For instance, from the 10th day 

 of September to the 13th, inclusive, we took 465,000, which was more 

 than enough to cover all losses to the impregnated eggs from all causes 

 combined. 



Loss from inherent causes. — I include under this head losses that 

 occurred with eggs that were already injured when they left the fish, 

 and which could not live under any circumstances, as, for instance, 

 eggs taken from dead fish, (chiefly by way of experiment,) and eggs 

 already dead when in the fish. This loss — if to be deprived of anything 

 which never had any value in the beginning may be considered a loss — 

 may be set at 30,000. 



Loss from excessive agitation. — This loss occurred, of course, in the ear- 

 lier stages of the embryo; agitation, though very fatal at first, being 

 harmless in the later stages of the eggs' development. The agitation 

 was caused (a) by the action of the supply-stream on eggs placed too 

 near the point where the stream falls into the hatching-troughs ; (b) by 

 carelessness of our Indian assistants in feathering the eggs when pick- 

 ing them over ; (c) by the action of the river-current on the eggs which 

 were placed in Seth Green's shad-hatching boxes. 



The first two causes need no comment. In regard to the third, I will 

 say that in experimenting with the shad-hatching boxes, we placed 

 some of them at first in too active a current, which gave the eggs so 

 much agitation that they became addled, and died. After a little expe- 

 rience, we learned what force of current they needed, and subsequently 

 had capital success with them. 



Mr. Woodbury informed me tbat after my departure he succeeded in 

 finding just what degree of movement in the water was required for the 

 salmon-eggs, so that his later experiments were attended with as good 

 success as we met with in the hatching-troughs. 



The losses from all causes of agitation combined I estimated at 100,000. 



Loss from want of impregnation. — The mortality from other causes was 

 not distinguishable from that resulting from want of impregnation, so 

 that it is impossible to ascertain what the loss from this cause was this 

 season. I should say, however, that the unimpregnated eggs numbered 

 less than 100,000, or 5 per cent, of the whole. This would place the 

 percentage of impregnated eggs at 95 per cent. I may add here that 

 on account of the abundance of salmon-eggs on the one hand, and the 

 scarcity of time on the other, it was often more of an object to save 

 time than to get a very high rate of impregnation. For instance, sup- 

 posing that, in taking 100,000 eggs, an hour should be consumed in tak- 

 ing pains to save 2 per cent, in the impregnation, the gain would be 2,000 



eggs. The same amount of time spent in catching additional salmon and 



27 F 



