Buller. — Illustrations of Darwinism. 89 



have been introduced in former times through human agency. 

 It will be remembered that the Maoris have a tradition that 

 the Pukeko, or Swamp-hen {Porphyrio melanonotus) — which, 

 until recent years, when its haunts were invaded and drained, 

 was excessively abundant in both Islands — was first introduced 

 by their ancestors, who brought tame birds with them in their 

 canoes from Hawaiki. It must be borne in mind also that the 

 range of the Grey Kiwi includes the north-west coast of the Nel- 

 son District, for specimens which I obtained from that locality 

 have been referred by Mr. Kothschild to his Apteryx occi- 

 dentalis ; and, furthermore, that the passage to and from the 

 Kapiti coast, on the opposite side of Cook Strait, could easily 

 be effected by the Maoris in their war-canoes. To entrap a 

 few Kiwis, and bring them across alive in flax cages, would 

 have been a very simple operation, and a far less ambitious 

 project than that of stocking New Zealand with the Swamp- 

 hen from far-off Hawaiki. The suggestion does not seem an 

 unlikely one, when we remember that the Kiwi was always 

 highly prized by the Maoris from the earliest times, both as 

 an article of food and on account of its feathers. 



On the theory put forward, and assuming, as w T e fairly 

 may do, that the North and South Islands have never been 

 united since the continental submergence, — in other words, 

 that there was a simultaneous elevation of the two areas, 

 north and south, with a permanent sea-channel dividing 

 them, — we can understand and account for the existence of 

 closely-allied representative species in the two Islands. I will 

 give some examples: In the North Island the Blue-wattled 

 Crow {Glaucojris zvilsoni), in the South the Yellow-wattled 

 Crow {Glaucopis cinerea) ; in the North Island the Saddle- 

 back {Creadion carunadatus) , and in the South its grey ally, 

 Creadion cinereus. It is true that Creadion carunculatus is 

 found also in the South Island, which is the proper home of 

 Creadion cinereus. This may, I think, be accounted for by an 

 .accidental colonization at some time, through the crossing of 

 stray individuals to the other side of the Straits : even a 

 single pair would suffice. Bare as this bird now is along the 

 wooded shore on the north side of Cook Strait, I can re- 

 member that about thirty-five years ago it w r as more abundant 

 there than in any other part of the country. But to resume 

 my list of examples : In the North Island we have the Thick- 

 billed Thrush {Turnagra hectori), in the South the common 

 Turnagra crassirostris ; in the North Island the Wood-robin 

 (2Iiro longipcs), in the South its congener Miro australis ; in 

 the North Island the Whitehead {Clitonyx albicapilla), in 

 the South the Yellowhead {Clitonyx ochroccphala) ; in the 

 North Island the White-breasted Tomtit (Myiomoira toitoi), 

 in the South the Yellow-breasted Tomtit {Myiomoira macro- 



