FISHERY AND SCIENCE 153 



tilised eggs, up to the moment of birth, is less than 2 per 

 cent. The aquaria for the fry are of wood lined with 

 zinc. The young are fed with the spleen of bullocks, 

 reduced to a pulp and passed through a sieve. 



Will marine piscifacture ever attain a great industrial 

 position ? I do not think so. A river is one matter ; the 

 ocean is another. The Americans were easily able to 

 replenish their rivers with shad, which had become ex- 

 tremely rare, and to acclimatise them in the rivers of the 

 Pacific Coast, which they had never frequented ; but this 

 does not prove that one can repeople a gulf or a bay. 

 However, the science should be encouraged, as its 

 principle is correct and its methods serious, and because 

 it is, like the fry it produces, an embryo which will 

 develop. 



II 



To fabricate larvae and to throw them into the sea : 

 that is the direct method of replenishment. Let us 

 consider all the conditions of the sea which are favour- 

 able to the prosperity of the various species ; this is the 

 indirect method. This leads us to oceanography. 



The North Sea receives, year in, year out, according 

 to Brandt, 487,000,000 kilogrammes (or about 487,000 

 tons) of azote in combination and in an utilisable con- 

 dition ; while its yield in the form of edible flesh is only 

 16,000,000 kilogrammes, or 16,000 tons. 1 It will be 

 objected that, as all the fish in the North Sea are not 

 captured, these figures do not express anything pre- 

 cisely. That is so ; but if we remember that the North 

 Sea is becoming poorer in fish they assume a great 

 importance, for they show that a great quantity of com- 

 bined and utilisable azote is not utilised. From this 



1 See p. 100. 



