Letters, Extracts, and Notes. 529 



Possibly Mr. Grant was himself mistaken as to the age 

 of some of his birds, as it is always hard to tell the age of a 

 bird from a skin. I have a note of a wild-killed hen, shot 

 early in November, in which the bill was red and yellow 

 but the throat was white — a state of plumage for that time 

 of year which is not mentioned ia Mr. Grant's paper. 



From careful comparison and other details of plumage, 

 I came to the conclusion that it was adult, and if so, some 

 adults must get a white throat in autumn. 



I have notes of several other minor details of plumage 

 not mentioned by Mr. Grant, such as white on the first 

 primary ; these details may, however, ouly be due to indi- 

 vidual variation, and as I have not got my skins here to 

 examine, it is not worth mentioning these matters in detail. 

 The fact, however, that Mr. Grant considered the white 

 throat confined to birds of the year may possibly have led 

 him astray on the colour of the bill. 



The red plate, as Mr. Grant suggests, undoubtedly swells 

 considerably, especially in the males, at the approach of 

 the breeding-season. 



J. Lewis Bonhote. 



Zoological Gardens, Giza, 

 April 21, 1914. 



Sir, — Mr. C. H. B. Grant's note, in the last number of 

 'The Ibis ■* (p. 298), on the fact that the Moorhen casts all 

 its flight-feathers at once, is most certainly " not altogether 

 new.^' It has been known to me at any rate, and also to 

 many of my ornithological friends, for at least a dozen years. 

 Moreover, in a paper (Ornis, ix. 1897-8, pp. 15-22) dealing 

 with those species which become incapable of flight during 

 the moul ting-season. Baron D'Hamonville reviews the results 

 of previous workers and adds observations of his own ; his 

 list includes the Moorhen. Mr. Grant seems to have over- 

 looked this paper, and it may be true that " no recent work 

 on British birds " refers to this moult, but then very few 

 recent general works have much to say about moult at all ; 

 I should have thought that this moult of the Moorhen, known 



