122 Letters, Extracts, and Notes. [Ibis, 



to be highly congratulated on the excellent way in which he 

 has carried out his difficult task of securing a photographic 

 record of our bird-friends in their native haunts. 



I am J Sir, 



Yours faithfully. 



Nils Gyldenstolpe, 

 Assistant, Vertebrate Department, 

 20 October, 1916. R. Nat. Hist. Museum, Stockholm. 



Corrections to Dr. van Someren's Paper. 

 Sir, — Will you kindly pul)lish the following corrections 

 to my papers in ' The Ibis ' of April and July 1916 : — 



Page 220. The type of Francolinus nahatii is in the 



Tervueren Museum, near Brussels, not Tring. 

 Page 433. Macro7iyx neivtoni, should read M. wintoni. 

 The locality Kyetema, wherever it appears, should read 

 Kyetume. 



Yours truly, 

 Nairobi, Bt. E. Afr. V. G. L. VAN SoMEREN. 



9 November, 1916. 



Directive-marks in Nestling's mouths. 



Sir, — I have lately seen Dr. Butler's letter in 'The Ibis' 

 for July, and 1 hasten to offer him my very sincere apologies 

 for a mistake that must have seemed inexcusable ; also to 

 express my regret to Mr. Pycraft in the same connection. 



I need not go into the reasons for the mistake, which 1 

 regret. But I take it that the application of the theory, as 

 it was stated in Mr. Pycraft's 'Infancy of Animals' and 

 discussed by Capt. Ingram and myself, is, actually, very 

 largely Mr. Pycraft's. At any rate, I judge from Dr. But- 

 ler's letter that his own suggestion was probably limited to 

 such ornamentation as we find (e.g.) in the flanges of the 

 beaks of the Estrildinae. With this much of the view I am 

 in hearty agreement. Capt. Ingram mentions the occurrence 

 of similar ornaments in Cinclus, Parus, and Troglodytes ('Ibis,' 



