306 THE BOTTOM OF THE SEA. 



and Spallanzani, it is surprising to find that authoi-s 

 living in times so far apart give similar details 

 respecting the inhabitants in this arm of the sea.* 

 Now we have seen that marine animals some.time ^ 

 emigrate, and leave their haunts to other species, if 

 the depth changes notably. Swordfish are now still 

 caught in the manner described by Polybius. 



Sometimes the movements of the terrestrial crust 

 are limited to a very small range of country — some- 

 times they embrace a very large extent. They are 

 nearly always compensated by inverse movements, 

 produced at more or less distant points. The gra lual 



* Polybius wrote, two thousand years ago : " The swordfish, sea- 

 dogs, and otlier cetaceous animals, become singularly fat every year 

 by living on the tunny-fish, which visit the coast of Italy in shoals^ 

 and which their enemies watch for in the straits. In fishing two 

 men are attached to each boat — one sculling, and the other standing 

 at tlie prow armed with a spear. The various boats have a common 

 scout, in an elevated situation, who signalises the approach of the 

 swordfish, for the fish swims with half his body out of tlie water. 

 When it approaches the boat the spearman strikes it with his spear, 

 the bead of which carries a barb, loosely fixed, so that it can be easily 

 detached when the spearman withdraws the handle. To tlie iron 

 head of the lance is fastened a long cord, which is let out to the 

 wounded fish, until by his continued struggles to escape he shall 

 have lost all his strength. Then they haul it ashore, or, if not, 

 take it on board their boat. If the spear-handle fall into the sea, it 

 is not necessarily lost; it is made of oak and spruce, in such a 

 manner that the oak sinking on account of its greater weight 

 permits the spruce to project above the surface of the water, so that 

 the fisherman may easily see and regain it. Sometimes it happens 

 that the rower is wounded, the swordfish being armed with a l<>ng 

 swoid, and being as furious and impetuous as a boar." 



