115 



velocity of the migration flight as detailed in previous pages. No 

 theory that could be devised would be likely, in all its details, to fit 

 in with such various speculations, and he may well look upon the 

 task as hopeless. 



In remarking on this wonderful power by means of which 

 birds find their way over such vast distances, his prefacing 

 words (p. 131) are not unopen to objection. He writes : " Man, 

 in spite of his senses and intellectual faculties, is not able to 

 continue moving in a straight line for even as much as a mile 

 in complete darkness or dense fog." A power of this description 

 varies greatly with individuals and even races, and the possession 

 of this sense of direction is very difficult of realisation by those 

 who are not so endowed. Complete darkness, moreover, is not a 

 condition of the atmosphere with which either man or birds are 

 familiar and there is abundant evidence to show, even in Herr 

 Gatke's book, that fog is just as puzzling to the latter as to the 

 former. It is an undoubted fact that in savage or nomadic man 

 this sense of direction, or power of orientation is highly developed. 

 Indeed, its possession is almost a necessity, for without compass 

 or other instruments, and with no knowledge of astronomy, 

 nomadic tribes have to undertake long journeys over desert and 

 trackless tundra in search of sustenance for themselves and their 

 domesticated animals. Man, of course, is in one respect at a 

 great advantage in comparison with birds, by reason of his ready 

 powers of intercourse with his fellow-men. A company of 

 savages will undoubtedly be more certain of eventually reaching 

 their destination than single individuals of the tribe. Naturally 

 the most experienced members of the company will be chosen as 

 pilots on these occasions. But here in the case of birds, a diffi- 

 culty arises, for it is undoubtedly a fact that it is the young, in the 

 great majority of species, which first set out from the breeding 

 grounds on the autumnal migration, and there is no reliable 

 evidence to prove that they are accompanied by older and more 

 experienced individuals as guides. Certain leading ornithologists, 

 however, have held the opposite view, and even so great an 

 authority as Seebohm states that the young are led by those 

 barren or otherwise non-breeding birds which are the avant 

 courier es of the migratory hosts (" Geog. Distribution Chara- 

 driidse "). 



