Vol. xxxiii.] 74 



The Hon. Walter Rothschild exhibited specimens of 

 Accipiter gularis (Temm. & Schl.) and made the following 

 remarks : — 



" I have brought for exhibition to-night an immature 

 example of Accipiter gularis, which seems to afford com- 

 plete proof of the theory put forward by Mr. Py craft at our 

 last meeting as the probable explanation of certain plumage 

 irregularities in the ducks in the passage to and from the 

 eclipse-plumage. In this bird there are on the left side of 

 the breast a number of feathers which are barred, as in the 

 adult, and not spotted. I have brought for comparison an 

 adult female and a normally marked immature bird of the 

 same species. It will be noted that the bands on the breast 

 of the adult bird are of a mauve-grey colour, while the spots 

 on the normally marked young bird are rufous-chestnut. 

 The immature bird, with the barred breast-feathers, has 

 evidently lost some of its first spotted plumage through 

 accident, and these have been replaced before the normal 

 moult took place. The papillae, or germs, responsible for 

 the production of these particular feathers, have produced 

 barred feathers, foreshadowing those of the adult, but 

 coloured with rufous-chestnut like those of the immature 

 bird. 



" 1 have also brought for comparison a series of immature 

 examples of three species of Birds of Paradise, Ptilorhis mag- 

 nifica, P. m. inter cedens, and Seleucides ignotus, together with 

 adult males and females of each. Various individual feathers 

 in the immature birds exhibit an admixture of adult and young 

 coloration in varying degrees, but if I read this problem 

 rightly, the explanation of this is not very different from 

 that of Accipiter gularis. From these examples and from 

 similar ones in a number of other species of Paradiseidse, 

 it seems clear that this mixture of colour is not due to the 

 accidental replacing of lost feathers between the moults ; in 

 the Paradise-birds the fully adult plumage is not assumed 

 for several years, and the feather-papillre take an irregular 



