SIDE IvIGHTS ON BIRDS 



will avoid threads stretched across the dark area 

 with absolute precision. 



But, in order to place the sight theory entirely 

 out of court, Dr. Eagle Clarke cites Sir J. C. 

 Ross in regard to the extensive migrations per- 

 formed by the flightless penguins. Penguins 

 were observed by him in great abundance going 

 eastwards, proceeding to their far-distant breeding 

 quarters, and Ross writes : — ' ' It is wonderful 

 instinct far beyond the powers of untutored reason, 

 which enables these creatures to find their way, 

 chiefly imder water, several hundred miles to 

 their place of usual resort, as each succeeding 

 spring season of the year arrives." On another 

 occasion Ross observed two penguins when more 

 than a thousand miles from the nearest land. 



Memory and Parentai. Guidance 

 It may be remembered in the " Cat's Pil- 

 grimage " Froude pictured the owl in the hollow 

 tree pondering the problem as to which first came 

 into the world — the owl or the egg. I^eaving 

 the initial difiiculty, certain writers have assumed 

 that the first bird-parents in some manner acquired 

 a knowledge of the route, and that in each suc- 

 ceeding generation the young birds are piloted 

 across the sea by their progenitors, who thus 

 bring memory and practical experience to bear 

 upon the choice of ways. Here, however, as 

 Dr. Eagle Clarke shows, a strong array of facts 

 bars the way. Numbers of examples are given 

 in which the young birds migrate apart from 

 their parents, and the author holds that this is 

 especially the case with species which are double- 

 brooded, when the first families are early cut 

 adrift and are left to shift foi themselves. In 

 further support of this contention Dr. Eagle 

 Clarke gives the instance of the cuckoo : — 



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