OPERATIONS IN CALIFORNIA IN 1873. 415 



found thesn satisfactory for maturing eggs in for shipment, though I do 

 not think fish hatched in the asphaltum troughs are as healthy as those 

 hatched in charcoal troughs. 



Seth Green's shad-box. — I also used, by way of experiment and with 

 Seth Green's permission, half a dozen of his shad-hatching boxes, anchor- 

 ing them in the river-current. They worked so well that I have no 

 doubt that, in a river of a warm- winter temperature like that of the 

 Sacramento, salmon-eggs could be hatched in them with perfectly satis- 

 factory results, which adds another merit to this very simple but won- 

 derfully effective invention. The only difficulty which we experienced 

 with the boxes was the inconvenience of getting at them to pick out the 

 dead eggs. On account of this inconvenience, I would prefer the station- 

 ary hatching-troughs if I had my choice, but should feel perfectly confi- 

 dent of hatching successfully any number of salmon-eggs with nothing 

 but the shad-boxes. 



The tent. — The whole hatching apparatus (excluding, of course, the 

 flume and wheel) was covered in as before mentioned by a large and 

 substantial tent 60 feet by 30 feet. The hatching-house, or, more prop- 

 erly speaking, hatching-tent, contained our work-bench and tools, and 

 was the place where all the mechanical work was done. 



0.— HATCHING THE EGGS. 



Considering that the eggs were matured under so many entirely new 

 conditions, and where eastern experience in hatching salmon-eggs fur- 

 nished in many points no precedent for a guide, I think the hatching 

 succeeded remarkably well. 



There were losses, however, the causes of which may be classed chiefly 

 under six heads : 



1. Loss by suffocation. 



2. Loss from direct rays of the sun. 



3. Loss from diffused light of the sun. 



4. Loss from inherent causes. 



5. Loss from excessive agitation. 



6. Loss from want of impregnation. 



Death of eggs by suffocation. — The loss that resulted from this cause 

 was very trifling. At the lower end of one of the lower troughs con- 

 taining some of the most advanced eggs, one of the division-cleats 

 separating the compartments had been made so high as to impede the 

 circulation of the water just above it, in consequence of which some of 

 the eggs in the water had an insufficient supply of air, and were suffo- 

 cated. I may add here that I have noticed that a vast amount more of 

 circulation in the hatching- water is demanded by trout and salmon eggs 

 at a late period of their development than at the earlier stages. When 

 these eggs are first taken, they can be literally piled together in heaps, 

 in water having a very slight movement, without danger ; but after the 

 embryo has shown itself distinctly in the egg, great caution must be 



