840 



BBITISH BIRDS 



Great Northern Diver. 



Colymbus glacialis. 



Fig. 115. — Great Northern Diver, i natural size. 



Bill black ; irides red ; head and neck black, glossed with 

 purple on the upper throat, and with green on the lower neck ; two 

 throat-bands black barred with white ; mantle black spotted with 

 white ; under parts white. Length, thirty-three inches. 



The great northern diver, or loon, is called great because he 

 exceeds the other divers in size ; in this sense he is also great in 

 relation to birds generally, since he is as big as a goose, and there- 

 fore the equal of the few species that are greatest. In form he 

 differs widely from the geese. An oceanic bird that escapes from 

 its enemies by diving, and is never seen on the wing except when 

 migrating, and never on land except when breeding, his form has 

 been modified so as to make swimming and diving as easy to him 

 as careering through the air is to the swift, and climbing on trees 

 to the woodpecker- The beak is straight, conical, and sharp-pointed ; 



