Wellington Philosophical Society. 651 



was perfectly true, but it would be found as a rule that the external 

 characters, such as the bill, feet, and wings, were but a reflex of the 

 internal organization; they must of necessity harmonize with each other, 

 the one being, in fact, the index of the other. For his own part, 

 he considered that, whatever might be the system of classification, 

 it was impossible to attach too much importance to the anatomical 

 structure of animals. In his opinion, as to the class Aves, there 

 never would be a perfect system evolved till the oesophagus and in- 

 testinal canal, as well as the osteological framework, of every bird had 

 been completely investigated by ornithologists, as that of the common 

 rock-dove (Columba livia) had been by the late Professor McGillivray. 

 As to the small amount of specific difference distinguishing these island- 

 forms from those inhabiting the mainland, this only went to prove that 

 at no very remote date in the past there was a parent species from which 

 these various forms had sprung, the differentiation of character having 

 been caused, under the operation of natural laws, by the insulation of the 

 descendants for the necessary period of time. For example, roughly 

 speaking, each group of islands possessed its own parrakeet, but th< se 

 were so closely related to one another that some naturalists regard them 

 all as mere local varieties of the typical Platycercus nova-zcalandice. Be 

 that as it may, no one can doubt a common parentage. The case is 

 different as between P. unicolor and P. crythrotis. Here we have two 

 parrakeets, possibly genericaHy distinct, living side by side on Antipodes 

 Island, a mere rock in the midst of the ocean. The larger form, P. uni- 

 color, has been there long enough to become highly specialized in its 

 structure and habits, having, as we see, become admirably adapted to its 

 natural environment. The other form, P. crythrotis, differs so slightly 

 from P. nova - zcalandicc that some ornithologists refuse to accord it 

 separate specific rank. As he had explained on a former occasion, he 

 could only account for the co-existence of the two species by assuming 

 an accidental colonization of the rock by the smaller red-topped form at 

 a comparatively recent date. As to Sir James Hector's criticism with 

 regard to Mr. Rothschild's Carpophaga clmthamensis, he (the speaker) 

 could hardly agree. He had himself shot hundreds of the New Zealand 

 wood-pigeons, and he was willing to admit that within early limits there 

 was much individual variation. But that was something very different 

 from the presence of constant specific characters, however slight. He 

 would undertake to pick out a Chatham Island wood-pigeon from a hun- 

 dred New Zealand birds, the difference of plumage being sufficiently pro- 

 nounced to make the bird readily distinguishable from C. nova,- zcalandicc. 

 That both birds had originally come from the same stock he had not 

 the slightest doubt. But, if we are to regard specific characters at all, 

 then for the purposes of clas-ification we must treat the Chatham Island 

 pigeon as distinct from our own. If a so-called "species" passes the 

 ordeal among expert ornithologists at Home, and is generally accepted as 

 such, we cannot lightly ignore the distinction ; but the very doubt raised 

 by Sir James Hector bears directly on the question of descent with modi- 

 fication. Dr. Sharpe's Porphyrio chathamcnsis, referred to by Sir James 

 Hector as a case in point, seemed to him entirely different; for this was 

 just one of those ordinary instances of individual variation. If, on the 

 other hand, all the specimens from the Chatham Islands had exhibited 

 the peculiarities in coloration of Dr. Sharpe's specimen, he (the speaker) 

 would have been willing to admit it as another illustration of the creation 

 of insular species by natural means. As he had pointed out, however, that 

 was not the fact. 



4. "On the Anatomy of Flight of certain Birds," by 

 Sir James Hector, F.E.S. (Transactions, p. 28-i.) 



Mr. Tanner asked if it was true that the penguin could only move 



