^"^igoJ'] Correspondence. 22 5 



While on the subject of the official list, I venture to enter my 

 protest against the haphazard description of new species on what 

 seem to me very slender grounds — slight differences in 

 measurement and shades of plumage. I do not think this should 

 be done without the examination of a large series of specimens, 

 both of island and mainland birds. Zosterops Jiabnaturiiia, in 

 particular, should be very carefully inquired into. This bird is 

 well known to vary considerably in plumage, and is also a very 

 strong flyer — witness its spontaneous appearance in New Zealand. 

 I have myself on more than one occasion seen flocks of these 

 birds several miles from land, and a seafaring friend told me 

 some years ago that a flock settled in the rigging of his ship 

 when about i,ooo miles from land. It is hardly to be supposed 

 that such a bird would have any difficulty in crossing Backstairs 

 Passage — about five miles. Moreover, the Zosterops on Eyre's 

 Peninsula is Z. avridescens. AcantJiiza hnlmatJirina has already 

 been examined by Mr. North, and the name A. .szV/-:;/ suggested, 

 in honour of Mr. R. Zietz, v/ho sent him the specimens. He has 

 not yet, I believe, ventured to describe it as a new species without 

 further evidence. As regards the other new species, I may state 

 that the S.A. ornithologists have been familiar for years past 

 with the Kangaroo Island forms, and have had opportunities of 

 comparing them with the mainland birds, and it has not hitherto 

 occurred to them that they required separation. — I am, &c., 



A. M. MORGAN. 

 Adelaide, 23rd February. 



PRINCIPLES OF MIGRATION. 



To the Editors of " TJie Emu!' 



Sirs, — In looking over Mr. Mattingley's interesting paper on 

 " The Principles Governing .... Migration in Birds," I 

 was astonished to read the following sentence, penned in all 

 seriousness — "The date of migration varying according to the 

 climatic condition of the season " {Emu, vol. v., p. 147). Now, 

 not alone do common-sense and the " reason " of which our 

 author writes so glibly, but hard fact, incontestably prove the 

 inaccuracy of the above statement. I do not claim to be a 

 " full-fledged " ornithologist, nor for the matter of that docs Mr. 

 Mattingley, so far as I am aware, and we therefore meet upon 

 tolerably common ground, but I do claim to have kept the 

 records of Irish migratory birds for more than fifteen years, and 

 to have closely studied the problems of their vernal migration. 

 During eight of those years I resided cither wholly or during 

 the springtime in Dublin, and it was my daily habit to stroll 

 for an hour before breakfast, inalf^rc the weather, along the 

 banks of the Dodder between Ballsbridge and classic Donny- 



