FISHERY AND SCIENCE 149 



which float upon the surface, may be fertilised in a 

 convenient receptacle, and will then develop in the 

 normal manner. The discovery was extended to other 

 species. Then the programme of pisciculture was 

 decided upon : it was to obtain and fertilise eggs, to rear 

 the young in an aquarium until they had attained a 

 certain size, and to place them in the sea. Its object was 

 proclaimed : to replenish exhausted fishing-grounds. 



But was not this a futile labour ? Sabin Berthelot, 

 Huxley, and Macintosh did not spare it in their writings, 

 and the subject has been hotly discussed. It would 

 certainly be puerile to seek to add to the formidable 

 quantities of eggs which drift at the mercy of the 

 currents. But the question does not assume this aspect. 

 The struggle for life diminishes the number of indi- 

 viduals. M. Cann has shown that in the seasons of 

 1894, 1895, and 1896 the density of natural reproduction 

 of soles between Treport and Dunkirk varied as ri, -3, 

 and '7 ; so that in 1895 the deficit amounted to three- 

 quarters of the spawning effected in 1894. In short, our 

 fishermen have to face a limited natural production. 

 Now three conditions are possible : either the number of 

 fishermen may be very small, so that an excess of fish 

 remains ; or their number may be constant, and the 

 available quantity of fish may remain constant; or the 

 number of fishermen may increase and the quantity of 

 fish diminish. The latter case is the most frequent. In 

 1820 there were 26,870 fishermen on the coasts of 

 France ; in 1900, nearly 100,000. Man therefore decreases 

 the natural production of fish ; and by man I mean more 

 especially the petty fisherman, whose devastating work in 

 our coastal waters we have already considered. Conse- 

 quently piscifacture will restore to the sea what it would 

 have produced had man not multiplied his catches; it 



