ART. 16. BIRDS PROM NORTH CELEBES RILEY. 59 



of the year, as some of the specimens in this stage have begun to 

 assume the black heads and throats of the next phimage. 



There is one specimen (No. 252550), Gimpoe, August 21, marked 

 as a female, that does not fall into any of the above stages and I must 

 confess that I do not know what to make of it. It is a bluish black 

 on the back, tail, and fore neck; the breast and belly buffy barred 

 with black; the old feathers of the wings (it is in molt) show a few 

 hardly discernible rufous irregular cross bars, the new feathers are 

 coming in bluish black. It resembles the male in the color of the 

 back and tail, but not otherwise. If the bird is wrongly sexed and 

 proves to be an immature male, it is still very remarkable, as I have 

 already shown that the young male when it leaves the nest is a 

 shining black like the adult. For a bird to acquire the adult dress 

 and then retrograde would be rather unique. I must confess that I 

 do not know how to interpret Meyer and Wiglesworth's description 

 of the nestling, except that it must be a female and that the sexes 

 differ widely in the immature plumage, even in the nestling, but 

 approach each other in old age. 



To recapitulate : The fully adult female resembles the adult male 

 but is duller. The young male resembles the adult male from the 

 nest up, while the young female has a distinctive immature dress 

 and only acquires the fully adult plumage after successive molts 

 covering a period of two or more years. The females breed in the 

 immature plumage, that is the stage with greenish black backs, black 

 throats, and cinnamon underparts, which is assumed in the second 

 year, judging from the material in the collection. This would ac- 

 count for the rarity of fully adult plumages of the female in collec- 

 tions as they would be overbalanced by immature individuals and 

 owing to the struggle for existance much fewer would ever live to 

 assume it. There is nothing new in the above interpretations of the 

 changes in plumage, except that the young male described above 

 seems to me to be the key to the whole situation and to settle the mat- 

 ter, leaving no ground for further argument. 



123. SCYTHROPS NOVAEHOLLANDIAE Latham. 



One male and one female, Rano Lindoe, March 11, 1917; one im- 

 mature unsexed, Lende, June 15, 1917. 



The two adults when compared with Australian specimens have 

 the backs less tinged with olive, and the top of the head a clearer 

 gray. The Australian specimens are old and unsatisfactory and 

 when new and larger series are compared the above differences might 

 not hold. 



The immature when compared with a specimen of about the same 

 age from Cape York, Queensland, has the throat and top of head 



