176 SEA FISHERIES 



as the spleen of bullocks ? Bar will eat sometimes fish, 

 sometimes crustaceans, sometimes marine algae, some- 

 times fresh-water plants, sometimes the refuse poured 

 out by the sewers. Bream live sometimes on vegetable 

 food, sometimes on worms, sometimes on fish ; herring 

 on sand-eels, molluscs, annelidae, and pelagic crustaceans ; 

 sardines on pelagic crustaceans, the larvae of molluscs, 

 and microscopic algae. 



Attack provokes defence. The two words, in short, 

 denote two aspects of the same thing. The weever, 

 with its poisonous spines, attacks weaker fish than itself 

 and defends itself against the stronger. The young sole, 

 by covering itself with sand, conceals itself both from the 

 prey it is waiting for and from its enemy. Means of 

 defence are legion. Their variety enables the naturalist 

 to comprehend the general plasticity of the living 

 organism. The crabs live in isolation, the better to hide 

 themselves, or gather together in order to present a 

 larger front of resistance. They keep near the shore, 

 out of the way of the large carnivora of the ocean. 

 In the shelter of the rocks we find the sar, girella, 

 bream, and gurnards. Behind the muddy curtain of 

 the shore waters we find the rascasse, or sea-frog, another 

 gurnard. Further out are the weevers, which half bury 

 themselves in the sand. Still further inshore are the 

 sand-eels, which bury themselves completely, and the 

 bulFs-heads or miller's-thumbs (Cottidae), which we find 

 at low tide crouching at the bottom of little pools. 



Not only do fish take the greatest possible advantage 

 of their surroundings, but they mimic them, and being 

 almost indistinguishable from them, they pass unper- 

 ceived. The wrass and young flying-fish take on the 

 colours of the rocks and the seaweeds which surround 

 them. The coloration of the sole harmonises with that 



