i82 THE WONDER OF LIFE 



whole answer, since many birds migrate by night and at 

 considerable altitudes. Nor are there any landmarks in 

 the open sea. 



(4) The fourth suggestion has almost certainly a high 

 degree of soundness, that birds have in a subhme degree 

 ' a sense of direction \ which is expressed in two forms — 

 as a capacity for flying continuously in a definite direction, 

 and as a capacity for ' homing '. In regard to the second 

 form we have some data, for the ' homing ' powers of cats 

 and dogs, cattle and horses, are well known. Even when 

 the cat is put in a basket, and taken in a cab, and then in 

 a train, it may find its way back. It is true that we do 

 not hear very much of the cats who left their second home 

 and did not return to their first home, but the positive 

 cases are very interesting. There are some striking facts 

 to which we shall refer in the chapter on Animal 

 Behaviour, which go to show that if a hive-bee, issuing 

 from the hive, be caught and imprisoned in a box and 

 put into a pocket, and be thus transported for an 

 intricate half-mile, and then released, it ascends into 

 the air, and makes a ' bee-line ' for home. The ' homing ' 

 of pigeons is also a familiarly established fact, and 

 the value of it is not lessened by knowing that the 

 power can be greatly increased by training. In fact, it 

 seems legitimate to suppose that birds have in a subhme 

 degree the sense of direction and the homing faculty. But 

 all that we can say is, that this not unwarranted assump- 

 tion makes the problem of way-finding less of an isolated 

 riddle. 



A Particular Case. — A story that may well excite 

 admiration is that of the Pacific Golden Plover [Chamdrius 

 dominicus fulvus), large numbers of which winter in the 



