A POT-HUNTER'S DEFIANCE 83 



two gallons or six times as much, as an Ostrich 



' * Don 't run away with the idea, though, that the 

 ^pyornis was six times as big as the Ostrich. 

 The size of the egg isn't always a clew to the size 

 of the bird. The Raven is twice the size of the 

 Guillemot, but his egg is considerably smaller." 



*'But what is it that makes birds' eggs all dif- 

 ferent?" queried Shan. 



''The same thing that makes birds all different," 

 was the answer; ''they have developed in different 

 ways during the millions of years that they have 

 lived on earth. It's too long a story to begin now, 

 how birds began. 



"So far as eggs are concerned, however, their 

 differences are of two kinds, texture of shell 

 and coloring. Sometimes the surface of a shell 

 is glossy, as in the Kingfisher ; or opalescent, as in 

 some of the Woodpeckers ; in the Tinamou, a curi- 

 ous good-sized bird of Guiana, something like a 

 Partridge in appearance, the eggs have a glazed 

 surface like burnished metal, peculiar to this bird 

 alone; the eggs of the Emu look as though they 

 had small-pox; the eggs of Ducks are greasy; 

 while they are rough, with a chalky film, in the 

 Gannet. 



