FISHERY PROBLEMS 187 



of marine life is no longer tenable ; the recent oceano- 

 graphic expeditions have exploded it for ever. The 

 womb of the ocean is the continental plateau ; the place 

 of acute and constant crises, the place where even in- 

 organic matter is not over-stable, while the floor of the 

 gulfs is rarely covered with anything but clay, the last 

 term of the mineral series. The creatures which people 

 the abysses are emigrant forms, driven from the upper 

 waters by the struggle for life ; they are the conquered. 

 They appear to live upon the bottom, grouped in oases 

 of some sort, in the desert darkness. 1 Is it rash to 

 suppose that these oases are due to states of crisis, 

 strictly localised and extremely feeble. The future will 

 tell us ... Venus Aphrodite, daughter of the sea-foam, 

 was born upon the shore. 



V 



Natural laws are always narrowly limited in their 

 bearing. They are provisional though convenient 

 formulae ; threads of Ariadne, which allow the seeker 

 to find his way through the labyrinth of phenomena. 

 If they have taught the technician a few certain methods, 

 they have fulfilled their office. Our theory of fisheries 

 is perhaps in a like case. 



By means of this theory, I think, we can, without 

 too great a probability of error, discover new fishing- 

 grounds. Take a thermometer, a good chart of 

 currents, and an ocean chart ; in an emergency the 



1 No light whatever reaches these depths, and most of the fishes 

 which inhabit them are possessed of phosphorescent organs. It 

 must be remembered that not only is the light absorbed by the 

 water in geometrical progression, but that only light incident at 

 a certain minimum angle can pierce the surface. From below, the 

 surface of a calm sea is seen as a black, trembling sheet, metallic in 

 appearance, with a great greenish circle of light overhead. [TRANS.] 



