LONDON BIRDS 61 



brown, like a dark Kestrel's egg, and others with spots 

 or vermicelli patterns of cinnamons, pale buffs, browns, 

 and purples on ground of as many tints. 



But and it is to this that the eggs of the Guillemot 

 owe their special interest endless as are the varieties 

 of colour of the species, there is little or no variety in 

 the colouring of the eggs of individuals, and it is thus 

 possible to identify birds, and to say with something 

 like certainty that the same pairs occupy the same 

 exact spots year after year. An egg of peculiar 

 marking and colour may be taken one day. If it is 

 early in the season there is every probability that ten 

 days or a fortnight later, and again and again in follow- 

 ing years, another egg to match may be found on 

 the same ledge ; climbers say, ' within half an inch ' of 

 the same position. Every one of the millions of old 

 Guillemots which gather in early summer from north, 

 south, east, and west to the great breeding-places has 

 her own appropriated small corner. 



From their painted eggs we may argue fairly con- 

 clusively that the Swallow which has this year occupied 

 the old nest under the eaves, and the Nightingale and 

 Willow Wren which have built among the grasses 

 and wildflowers in the favourite corner outside the 

 wood, are the very birds which we saw and heard in 

 the same places last year. The ' homing ' instinct is a 

 law of nature to which birds and men alike are subject. 

 Guillemots and Razorbills, which, excepting in the 

 form of the beak, are very much like them, are the 

 commonest of the black and white birds which, on 



