THE LANDINGS 119 



Ireland, contains only about 80,000 souls ; 

 but its indented coast-line is well suited to a 

 fishing population, who find ample harbour- 

 age for their small boats in the numberless 

 fjords, and have easy access to the prolific 

 fishing banks which entirely surround the 

 coast. 



Experience shows us that off the bleak 

 inhospitable coasts of Northern Europe 

 and America we find conditions for fish 

 life much better than those prevailing in 

 tropical seas. In comparing land and 

 sea conditions we notice that density of life 

 is, unless there are exceptional circum- 

 stances, always greatest at sea-level. In 

 the lowland plains of the world there is a 

 density of animal and plant life which 

 dwindles as we ascend the different alti- 

 tudes. This applies in inverse way in the 

 sea. Life is greatest near the surface and 

 coast level, and dwindles as we descend into 

 the depths. This naturally brings land and 

 sea life in proximity. Conditions are rather 

 different, however, in high latitudes. In 

 the polar circle, animal and plant life are 

 almost absent on the laiyl, but in the 

 sea the mass of living jelly, the plankton, 



