192 



OUR GREATEST TR.W'ELERS 



THE ROBIN MOVES MUCH QUICKER ON THE PACIEIC THAN ON THE ATLANTIC 



The dotted lines cnnnect the places at which the rohins arrive simultaneously. The heavy 

 solid line marks the division between the eastern and the western forms. The heavy dotted 

 line represents the migration route of the .\laska breeding- birds (see pages 190 and 193). 



