520 Letters, Extracts, and Notes. [Ibis, 



I do not like to appear to doubt the accuracy of 

 Mr. Mathews' collectors, but I must say I should be 

 exceedingly interested and very surprised if he could tell 

 me that he had himself examined in the flesh any of the 

 following : — 



1. An adult male Roseate or Leadbeater's Cockatoo with 



a red or pale brown iris. 



2. An adult female Roseate or Leadbeater's Cockatoo 



with a black iris. 



3. A female Platycercus icterotis, with normal repro- 



ductive organs, with the entire head, neck, and 

 breast bright crimson, unmarked with gi'een or 

 yellow, and bright yellow cheek-patches like a male's. 



4. A female Purpure'icephalus spurius, with normal repro- 



ductive organs, which has a bright red cap, unmarked 

 with green, and cheeks as bright as a fuUy-plumaged 

 male's. 



It does seem strange that all, or nearly all, birds of the 

 species just mentioned, that have been imported alive into 

 England, should belong to local races possessing peculiarities 

 which have not been detected in Australia — especially so in 

 the case of the Roseate Cockatoo which used to be brought 

 over in hundreds. 



I can quite understand that preserved skins would not 

 show a difference in size between the heads of male and 

 female Platycercus and Barnardius Parrakeets, but I should 

 expect a difference in skull measurements, and also a con- 

 stant superiority of males over females of the same age and 

 race in the measurement of the upper mandible across its 

 widest portion. 



I must suspend judgment on the question of the age at 

 which PJatycercine Parrakeets assume adult plumage in 

 their native land, but it is a very odd thing and quite 

 contrary to the whole experience of aviculture, if conditions 

 of captivity which lower the bird's vitality and tend to 



