BIRD LIFE 241 



her nest. The bird rose as the spot was approached, but 

 ten minutes' search or more by two pairs of eyes, not 

 unpractised in looking for birds' eggs, failed to dis- 

 cover the nest. It was not until the keeper, who had 

 been called in to help, had freely relieved himself by 



strong language levelled at ' them Carrion Crows, 



which won't leave a thing in the place,' that a glossy 

 Maltese cross of four pear-shaped green and brown eggs, 

 mottled in exact imitation of the wet moss around it, 

 revealed itself to all three at once, in the middle of 

 a tuft of sprits. 



A favourite breeding-place of the Lesser and Com- 

 mon Terns is a pebble- covered flat, not far above 

 high-water mark, near the mouth of a tidal harbour in 

 Norfolk. Here, too, the likeness of the eggs to their 

 surroundings is so close that only a very sharp eye, 

 unless by accident, is likely to find a nest. A few 

 handfuls of selected stones from the beach have, as an 

 illustration of protective colouring, been placed in a 

 glass-covered box (11 in. by 6 in.), with a few scraps 

 of dry seaweed and other odds and ends gathered 

 on the spot, and among them two or three eggs 

 of each species. When the box, placed in a good 

 light, is uncovered for a quarter of a minute, or even 

 longer, it is the exception for any one seeing the con- 

 tents for the first time to count the eggs correctly. 



The ' survival of the fittest ' seems rather a heartless, 

 and not, perhaps, very convincing, explanation of a 

 beautiful provision for the safety of a helpless embryo. 

 But, so far, it is the best that pure science can offer. 

 Q 



