186 SEA FISHERIES 



encounter of two critical conditions^ one biological and 

 the other oceanic. When the French briar the giant 

 white heather blooms only at the end of the stems, 

 the winter will be mild, and the spring will bring few 

 sardines to the Breton coast ; but when the briar is 

 covered with bloom the winter will be severe, and the 

 sardines will be plentiful in spring. 



To explain the correlation I have just been expressing 

 is a difficult matter, and at present, no doubt, im- 

 possible. Certainly the unstable equilibrium of the fish 

 agrees very well with its actual independence. We 

 may obviously maintain that a fish for which the 

 maximum temperature is 60 will prefer to waters 

 constantly at that temperature waters which attain their 

 temperature on the spot, deriving from two currents, 

 one at 59 and one at 61, or one at 55 and the other 

 at 65, and so forth. It is probable that there is a 

 sympathetic affinity between the critical state of biology 

 and the critical state of oceanography : but this is a 

 matter of metaphysics. I will adhere rather to positive 

 observations. By definition, the critical state is a mor- 

 phogenic state. As a matter of fact, it is at the surface 

 and near the coasts that the oceanic circulation is most 

 perceptible ; and the circulation and agitation of the 

 waters, and their fluctuations of temperature, are im- 

 portant factors in the modelling of the coasts and the 

 shaping of new formations ; for instance, recall the 

 Newfoundland banks. These factors also result in an 

 abundance of food, and, a little further out to sea, in 

 an abundance of plankton. Remember the miraculous 

 catches in the estuary of the Elbe. These conditions 

 are also indispensable to the life of fry, to their growth 

 and metamorphosis, and to the fattening of fish. The 

 idea that the abysses of the oceanic world saw the origin 



