WILD LIFE OF ORCHARD AND FIELD 



these winged wanderers of the sea alone render 

 populous, is not easily explained. Nor can we 

 readily understand how once a year the salmon 

 comes back (from conjecture only guesses where), 

 not to the coast alone, for that would be no more 

 than an ordinary case of migration, but to the 

 identical stream where it was born; and to prove 

 that it was not a blind emotion that led it would 

 be harder than in the case of the pigeon, the bee, 

 or even the frigate-bird. Yet who knows that 

 the fishes may not be able to perceive the dif- 

 ferences in the water which we designate "vari- 

 ations of temperature and density," or still more 

 delicate properties, and thus distinguish the fluid 

 of their native place from the outside element? 

 It is a question, however, whether this phe- 

 nomenon comes properly within the scope of this 

 article. 



Many domestic animals show a true homing 

 faculty, and often in a degree which excites our 

 surprise. One of the most remarkable cases I 

 knew was that of two of the mules of a pack-train 

 which, plainly by concerted action, left our camp 

 one morning without cause or provocation. We 

 were in southwestern Wyoming, about seventy- 

 five miles northwest of Rawlins Station, where we 



227 



