350 DR. A. 6. BUTLKU OX THE PLUMAGE [Dec. 1, 



3. On the Development of the Adult Colouring in the Yellow- 

 billed Cardinal {Paroaria capitata) from S. America. 

 By Akthur G. Butlee, Ph.D., F.L.S., F.Z.S., &c. 



[Received November 17, 1903.] 



In the ' Avicultural Magazine' for. July 1903 (pp. 294-298) I 

 had occasion to point out that Petronia albigularis of Brehm was 

 not an immature plumage of P. dentata, but a distinct species, 

 specimens of both birds having been in my possession for over five 

 years, and, though unaccompanied by a cock of either species, 

 building and laying at intervals during the whole time in which 

 I owned them. 



In the same Magazine for December 1903 I have a short paper 

 with an opposite tendency, dealing with two forms of Paroaria 

 which have hitherto been regarded as distinct species. I have 

 not, however, entered into details, in that brief account, of the 

 method of the growth in colour which gradually established the 

 identity of the supposed species : this I now propose to do. 



In July 1893 I imported a fully adult male of Paroaria capitata 

 in perfect plumage; unhappily it was subjected to rough treat- 

 ment during the journey home from La Plata, and so only 

 survived about six months. However, I had a beautiful skin made 

 of it, thus enabling me to have something better than a mere 

 illusti-ation for future reference. 



This year (September 1903) a consignment of Lesser Cardinals 

 was brought into the London bird-market by an Italian, who sold 

 his stock to an enthusiastic friend of mine, Mr. J. B. Housden 

 of Sydenham, who later bi-ought some of the Cardinals to me as 

 " Yellow- billed Cardinals" (P. capitata); but, as soon as I saw 

 them, I knew that the more advanced examples were unquestion- 

 ably the so-called Brown-throated Cardinal (P. cervicalis) ; some, 

 however, were fortunately in the interesting nestling dress. I 

 secured four specimens in various stages of colour-growth. 



The young bird at first is somewhat browner above than the 

 adult, the white of the under surface less pure ; the flanks ash- 

 grey ; the head and gular streak pale sandy buff excepting the 

 region of the so-called " crest " [P. cucuUata is the only species 

 with a true crest) which is purplish ashy ; the beak ochre-yellow, 

 with the tip and the culmen and tomium of the mandible blackish ; 

 tarsi flesh-pink, slaty-grey in front. 



The complete change from this plumage to the fully adult 

 colouring appears to take from nine to ten weeks ; and during 

 the whole time not a single feather is moulted out, but each 

 feather gradually changes from day to day. I am certain of this, 

 because I put the youngest bird with one more advanced in a 

 large box-cage, so that no feathers could be dropped without the 

 certainty of their beinji seen Iving on the sand ; moreover, the 



