FISHERY PROBLEMS 181 



the Anabas scandens, can climb a tree. The dactylopterus 

 or " flying gurnard " of the Mediterranean can both swim 

 and fly a distance of 100 to 200 yards, by the aid of its 

 pectoral fins, which are three-fifths the length of the fish. 

 The fifty species of exoccetae, or flying-fish, fly in flocks 

 for hundreds of yards. Whether it is the necessity of 

 obtaining food or a necessity of defence that drives these 

 creatures out of their usual environment matters little 

 for the moment ; the essential fact is that the pheno- 

 menon exists, and thanks to the action of time has given 

 rise to special adaptation. This exodus followed by return 

 operates within the narrow limits of the normal habitat. 

 The first zostera, now marine plants, came of old from the 

 shore. The first flying-fish and the first leaping fish leapt 

 and flew above their proper region. Imagine the dogs of 

 Constantinople beginning to live in the brooks, the sewers, 

 and the puddles of their respective quarters ; in a word, 

 leaving their environment without leaving their quarters ! 

 This remark does not apply only to the striking and 

 exceptional cases which I have just described, but also to 

 the very numerous and frequent and therefore normal 

 cases which I am about to consider. What shall we say 

 of the sea-trout, the shad ; the sturgeons, the salmon, and 

 the Seine smelt, which ascend our rivers at spawning- 

 time ; of the bar, dabs, plaice, and even soles, which 

 cross the limits of our estuaries ; of the dabs or flounders 

 of our rivers, which venture as far as Andelys, Malines, 

 and Gand ; of the eels, which make their way to the sea 

 if not that they all radically change their environment ? 

 And what else do all the other species which come in- 

 shore in shoals to spawn and to obtain more plentiful 

 food the bull-head and the gilt-head, omber and grey 

 mullet, which penetrate the creeks, salt-marshes, lagoons, 

 and fishponds of the coast in their search for brackish 



