WILD LIFE OF ORCHARD AND FIELD 



that local cuckoo which annually comes from the 

 Fiji Islands to New Zealand to breed, and then re- 

 turns to Fiji. These islands are fifteen hundred 

 miles apart, north and south, with nothing be- 

 tween. 



It is useless to pretend to explain how these 

 birds know and are able to keep their course over 

 these wide and windy spaces of ocean. We must 

 wait until we get more information before offering 

 even a guess at it. Possibly the investigations 

 and experiments now being pursued by such a stu- 

 dent as Professor Jacques Loeb, of the University 

 of Chicago, may some day solve the problem, by 

 the finding of some sort of "tropism" to which 

 migrating birds conform. 



Let us now go back to the more familiar and 

 comprehensible ways of our own land birds. 



The travelling at night seems an odd thing until 

 we study it. Then it becomes evident that, other- 

 wise, birds could have no time to get sufficient sub- 

 sistence. Their food comes to most of them in so 

 small particles, and their digestion of it is so rapid, 

 that it requires almost incessant effort to supply 

 their needs. That this is the secret of the night 

 journeys is shown by the fact that such birds as 

 swallows, swifts, night-hawks, certain birds of 



116 



