308 A BOOK-LOVER'S HOLIDAYS 



or over, from the next. In one such breeding 

 colony I counted a httle over a thousand eggs; 

 there were several of smaller size, and a few 

 that were larger, one having perhaps three 

 times as many. A number of the eggs, perhaps 

 ten per cent, had been destroyed by the gulls; 

 the coons had ravaged some of the gulls' nests, 

 which were in or beside the scrub. The eggs of 

 the terns, being so close together and on the 

 bare sand, were very conspicuous; they were 

 visible to a casual inspection at a distance of 

 two or three hundred yards, and it was quite 

 impossible for any bird or beast to overlook 

 them near by. These gregarious nesters, whose 

 eggs are gathered in a big nursery, cannot profit 

 by any concealing coloration of the eggs. The 

 eggs of the royal and Cabot's terns were per- 

 haps a shade less conspicuous than the darker 

 eggs of the Caspian tern, all of them lying to- 

 gether; but on that sand, and crowded into such 

 a regular nursery, none of them could have 

 escaped the vision of any foe with eyes. As I 

 have said, the eggs of the skimmer, as the 

 clutches were more scattered, were much more 

 difficult to make out, on the shell beaches. 

 Concealing coloration has been a survival fac- 

 tor only as regards a minority, and is respon- 

 sible for the precise coloration of only a small 



