Letters, Extracts, and Notes. 521 



for venturing to write is the circumstance that I feel a 

 natural concern that every detail made public about 

 Mr. Hawker should be accurate, since the place from which 

 I write was his, and every day 1 have to thank him for a 

 home made interesting and beautiful by his knowledge aud 

 his care. 



I am, Sir, 



Ashford Cbace, Your obedient servant, 



Petersfield, Hants. AuBYN Trbvor Battye. 



15 May, 1916. 



Directive-marks in Nestling Birds. 



Sir, — In Mr. C. F. M. Swynnerton^s interesting paper 

 on the '• Coloration of the Mouths and Eggs of Birds,'' 

 Ibis, antea, p. 274, he says that the " directive-marking " 

 explanation, undoubtedly applicable in certain cases, is 

 "Mr. Pycraft's.'' Is this a fact? 



The question as to who first published the explanation is 

 not a very important one, since it is one which might occur 

 to any reasoning being ; but it is well to be accurate in 

 even trifling matters. 



On December 1898 I published a short article in ' The 

 Avicultural Magazine,' 1st ser. vol. v. pp. 25-27, in which 

 I expressed my conviction that the ornamentation of the 

 mouth in the young of PoephUa mirabilis was merely a guide 

 to the parents when feeding their nestlings, and I quoted 

 Mr. St. Quintin and Mr. Meade-Waldo as agreeing with me 

 in this view of its object. 



I subsequently gave examples of the nestlings to the 

 British Museum, and talked the matter over with Mr. 

 Pycraf t, who also approved of my view ; but if, previous 

 to that date, he had published any observations on the 

 subject^ he did not inform me of the fact. 



Yours faithfully, 

 " The Lilies," A. G. Butler. 



124 Beckenbam Road, 



Beckenhani, Rent. 

 14 April, 1916. 



