EGGS. 41 



Megapodes raise a huge hot-bed of dead leaves wherein to deposit their eggs, 

 and the young are hatched without further care on the part of either parent. 

 Some of the Grebes and Eails pile fragments of aquatic plants on some growing 

 water weed. Gulls, Sandpipers, and Plovers lay their eggs in shallow pits. 

 The Einged Plover commonly places its eggs on shingle. Flamingoes erect 

 mounds of earth two feet high. The Shelduck beds its nest with down from 

 her own body. 



EGGS. 



Number. The eggs laid in one nest which are sat upon together and hatched 

 about the same time are called a dutch. Their number, though tolerably uniform 

 in each species, varies greatly in different species. Some birds have only one, 

 others two, and the majority of species four or five. Higher- numbers are less 

 common, but eight to twelve eggs in a clutch are frequent among Ducks and 

 Kails, and even more among some game birds. Examples : — 



Single egg. Manx Shearwater, Kazorbill. 



Two eggs. Black Guillemot, Swift, Eingdove. 



Three eggs. Oyster-Catcher, Sand-Grouse. 



Four eggs. Golden Plover, Common Sandpiper. 



Five eggs. Kestrel, Eobin. 



Nine eggs. Long-tailed Tit. 



Twelve eggs. Eed-legged Partridge. 



Form. In form, eggs may vary from almost spherical to different modifications 

 of elliptical or oval. The latter form, in which one end is smaller and more 

 pointed than the other, though not universal, is the most frequent, and dis- 

 tinguishes the eggs of birds from those of reptiles. If there are many eggs in 

 the nest, it is obvious that the conical form makes close packing more easy. 

 Where only two eggs are laid they are seldom conical. Eggs having a pyriform 

 shape, or narrowing very rapidly towards the smaller end, are mostly those of 

 birds (as Ldmieolce) which lay four in a nest, and are large in proportion to the 

 size of the bird. Their pointed ends being turned inwards, they occupy as little 

 space as possible, and are thus more easily covered by the brooding parent. 

 A conical egg placed on the ground or ledge of rock is less liable to roll away 

 from its place if disturbed than one of a spherical form. Examples : — 



Spheroidal. Scops Owl, Tawny Owl, Green Bee-Eater, Diving Petrel. 



Elliptical. Nightjar, Sand-Grouse, Shag. 



Biconical. Grebe. 



True oval. Wild Turkey, Dipper, Grey Partridge. 



Conical or Pyriform. Dunlin, Ja9ana, Lapwing, Guillemot. 



Size. The size of the egg has generally, but by no means constantly, some 

 relation to that of the parent bird. It also depends very much upon the degree 

 of development the young bird attains at the time of hatching. In the caSe of 

 birds in which the young are hatched in a very immature and helpless state, the 

 eggs are small relatively to the size of the parent. These birds usually build 

 carefully constructed nests suitable to contain the young birds during the first 

 period of their existence. When the young are well clothed with down, and can 



