1922.] Letters, Extracts, and Notes. 221 



That both birds were of tlie same species, and that the 

 species was Egretta garzetta I have no doubt. In size, 

 form, and actions — in everytiiing but colour of plumage 

 and soft parts — they were identical. The grey bird had 

 a greenisli-yellow bill and olive-green legs, in contrast with 

 tlie black bill and legs of its white companion. I was 

 carrying a ]Mauser rifle and only some soft-nosed bullet 

 cartridges, and though I could easily have killed the grey 

 bird with this, I hesitated to do so, feeling sure that I 

 should spoil it as a specimen, and expecting my men to 

 come up with my shot-gun at any minute. Unfortunately 

 before their arrival both birds rose together and flew out of 

 sight, the grey bird flying closely behind the white one. 

 Again, on the wing, the similarity of the birds in size, 

 shape, and wing-stroke — in everything but colour — was 

 exact. 



I am well acquainted with both the grey and the white 

 forms of Demiegretta schistacea (and with two other species 

 of dimorphic Reef-Herons), and I am certain that I did not 

 mistake two birds of this species for Egretta garzetta. 

 Moreover, the delicate blue-grey of the coloured bird was 

 quite different from that of Demiegretta schistacea, being 

 entirely free from any bhickish or slaty tinge. 



I quite anticipate that the correctness of my identification 

 will be doubted, being unconiirnied by the securing of the 

 bird, and for this reason I have had considerable hesitation 

 in offering this note to 'The Ibis.' But I sludl remain 

 convinced that the bird exemplified a reversion to an 

 ancestral phase in the evolution of Egretta garzetta which 

 must be of extremest rarity ^in this species, in which no 

 tendency to diuiorphism has hitlierto been recorded. 



A. L. BUTI.EK. 



St. Leonard's Park, 



Horjrliam, 

 14 November, 19i']. , 



