Letters, Exlracts^ and Notes. 653 



than appears to be normal [cf. notes re second plumage, 

 December to April). 



I think Mr. Bonhote is right in thinking the white on 

 tlie first primary is variable. I agree that we are all liable 

 to be mistaken, and if later Mr. Bonhote and Dr. Ticehurst 

 will allow me to examine their specimens in winter dress 

 and they prove to be adults with olive bills, I am quite 

 pi'epared to be convinced that my conclusions are 

 incorrect. 



I should especially like to examine Dr. Ticehurst's speci- 

 mens which he mentions as being taken on October 10 and 

 November 18, both of which are in that state of dress, and 

 should have the soft parts as given by me on p. 300 (second 

 plumage). Is not bis bird, taken on November 1, in adult 

 dress ? 



As regards Dr. Ticeburst's letter, he might be interested 

 to know that I showed my "flapper'''' Moorhens to several 

 ornithologists, who did not recollect having actually seen 

 specimens in that state ; anyway, I have not pretended that 

 the fact was new, but that it merely required resurrecting. 

 I note Dr. Ticehurst agrees that the shield increases in size 

 during the breeding-season. 



At a meeting of the B. O. C. during this last session, 

 Mr. Witherby exhibited a series of Rooks, the value of which 

 was that they were all taken during one year, and I think 

 that one yearns series would more surely fix times of season- 

 able moults and plumage than odd specimens secured over 

 a long period. 



I agree with Dr. Ticehurst that " series from about the 

 same dates of hatching '"' would be useful, but how to be 

 sure that birds on the wing were all hatched on a certain 

 date is beyond me, and after all, if chicks are hatching 

 from May to July, they would all be moulting into the 

 second plumage between the beginning of September and 

 the middle of November, a period of ten weeks, which 

 allows for about the same ratio of time as May to July ; 



SliR. X. VOL. II. 2 X 



