THE GREAT WHITE HERONS. 73 



of the bushes, so that it was exceedingly difficult to get up 

 and look into them. The three eggs which nearly every nest 

 contained looked almost lost in the middle of such a big plat- 

 form. There was a considerable mess on the ground beneath 

 each nest, from the birds dropping their excrement over the 

 edge of the nest. In only one nest did I find as many as four 

 eggs." 



Eggs. — Three or four in number, of a greenish-blue colour. 

 Axis, 2*1 5-2*45 ; diam., i"65-i'75. They vary somewhat in 

 dimensions, and some are slightly paler blue than others. They 

 are often laid in March in England, but a little later in Scotland, 

 and in parts of Europe not till May and June. 



THE GREAT WHITE HERONS. GENUS IIERODIAS. 



Herodias^ Boie, Isis, 1822, p. 559. 



Type, H. egretta (Wilson). 



Though very much resembling the True Herons in structure, 

 the Great White Herons may be distinguished by their snowy- 

 white plumage and by having the edges of the mandibles not 

 serrated, but a distinct sub-terminal notch is evident near the 

 tip of the bill. The latter is long, as in most Herons, but the 

 culmen does not exceed the length of the middle toe and claw. 

 There are no crest plumes, but all the species carry an enor- 

 mous dorsal train during the breeding-season. 



It is extremely difficult to say how many species of Herodias 

 exist. I have recently devoted much study to the Herons, 

 which are very difficult birds to understand, and none are 

 more so than the Egrets ; but I have come to the conclusion 

 that there are three species of Great White Heron, of which the 

 European species {H. alba) has a black bill in summer, while 

 the American bird (// egretta) and the Chinese bird (Z^ timo- 

 riensis) have yellow bills in summer. As, however, our own 

 H. alba has a yellow bill in winter like the other two species, 

 it is extremely difficult to recognise them apart at that season 

 of the year, but the colour of the bare tibiae may ultimately be 

 found to be a character of worth. //. egretta has the tibia black 

 like the tarsus, while //. alba and H. timoriensis have them 

 light-coloured. 



