HOW ANIMALS GET HOME. 201 



and renew their journey in the morning. When snow dis- 

 guises the landscape, also, many pigeons go astray. None 

 of these circumstances seriously hampers the semi-annual 

 migrations of swallows or geese. They journey at night, 

 as well as by day, straight over vast bodies of water and 

 flat deserts, true to the north or south. Homing pigeons 

 fly northward or southward, east or west, equally well, and 

 it is evident that their course is guided only by observa- 

 tion. Watch one tossed. On strong pinions it mounts 

 straight up into the air a hundred feet. Then it begins 

 to sweep around in great circles, rising higher and higher, 

 until if the locality is seventy-five or one hundred miles 

 beyond where it has ever been before it will go almost 

 out of sight. Then suddenly you will see it strike off upon 

 a straight course, and that course is homeward. But take 

 the same bird there a second time and none of these aerial 

 revolutions will occur its time is too pressing, its home- 

 sickness too intense for that ; instantly it turns its face 

 toward its owner's dove-cot. 



These facts mean something. They show that two defi- 

 nite intellectual processes serve to decide for the bird the 

 direction he is to take observation and memory. He gets 

 high enough, and turns about times enough, to catch sight 

 of some familiar object, and he makes for it ; arrived there, 



