THEIR REPRODUCTION (EGGS) 291 



remarkable. A Jack Snipe, for instance, a bird 

 not much bigger than a Sparrow, lays an egg 

 considerably larger than that of a Magpie, and 

 not much inferior to that of a Crow. A Guille- 

 mot's egg is as large as that of the Golden 

 Eagle, the average actual measurements of the 

 former being 3.3 inches by 2.0 inches, whilst 

 those of the latter are 2.9 inches by 2.3 inches. 

 Whether the number of eggs to be covered by 

 the parent during incubation determines the size, 

 or whether the state of the young when hatched 

 (the largest eggs relative to the size of the 

 mother producing the most precocious chicks) 

 be the influencing factor, we are as yet unable 

 to say. Possibly both facts may exert some in- 

 fluence. The connection between relative size, 

 shape, and number appears certainly to be an 

 intimate one. There is considerable diversity 

 in the number of eggs produced for a clutch 

 or sitting. Species, for instance, like the Gannet, 

 the Guillemot, the Petrels, the Puffin, and the 

 Tropic Bird lay one egg only for a sitting ; 

 Pigeons, Eagles, Vultures, Goatsuckers, Hum- 

 ming-Birds as regularly produce two for the 

 same purpose ; Gulls and Sand-Grouse three ; 

 whilst the Sandpipers, Snipes, and many Plovers 

 as regularly lay four. Most of the Passeriformes 



