XVI 



INTKODUCTION. 



impossible even to conjecture*— for the inhabitants of each island to develop new characters 

 suited to their special environment in each case, thus bringing into existence in the end the 

 various species of~Dinornis and its allies as we now know them ; that a widespread upheaval or 

 elevation of the land followed, reuniting most of the islands, and resulting in the areas now 

 known to us as the Islands of New Zealand, when, of course, the Struthious birds which had been 

 developed in the smaller insular areas would be able, in process of time, to commingle on common 

 ground. " In process of time," I say, because it would naturally take a considerable time for the 

 newly-elevated areas to become covered with vegetation, although, on the other hand, it is quite 

 possible that this elevation may have been gradual in its operation everywhere. I suggested that 

 when, by the gradual subsidence of their domain beneath the waters of the great Pacific, they 

 were driven as it were into a corner and overcrowded, the struggle for existence became a severe 

 one, and the extinction of the race then commenced ; that the more unwieldy giants, thus cabined 

 and confined, were the first to succumb ; and that the smaller species, perhaps in course of time 

 differentiated from their ancestors by the altered physical conditions of their environment, con- 

 tinued to live on till their final extirpation by man within recent historic times. Professor 

 Hutton supposes two successive submergences and elevations of the land at long intervals, but in 

 this I am unable to follow him. Without that, the theory is sufficient, I think, to account for the 

 co-existence in comparatively recent times of the various genera and species. But, as the 

 modifications in form and structure constitute important generic distinctions, very long periods of 

 time must have elapsed after the continental submergence before the final elevation of the land 

 which made it possible for these wingless birds to commingle as they evidently did in later times. 

 On the assumption that the North and South Islands were never reunited after the great sub- 

 mergence, these two areas having been independently formed by the fusion of different sets of 

 islands, north and south, when the elevation took place, this theory will account for the singular 

 fact that the Dinornis remains found in the North Island represent different species of birds from 

 those of which remains have been so abundantly discovered in the South. 



Professor Hutton had been of opinion that the smaller forms of Palseognathae in New Zea- 

 land must have preceded the larger ; and the fact that bones of only the smaller species of 

 Dinornis and Syomis have as yet been found in both Islands seems to favour that view. But 

 the evidence on this point is, I think, far from being exhausted, for fresh discoveries of Moa-bones 

 are still being made from time to time, and in the most unlikely localities. On the other hand, 

 whatever date may be assigned for the extinction of the Moa (and upon this question there is 

 much difference of opinion), there seems little doubt that the colossal forms, such as Dinornis 

 maximus, D. altus, D. validus, and D. excelsus, were the first to become extinct, because none of 

 their remains have ever yet been found in the ancient kitchen-middens, mixed up with the 

 rejectamenta of human feasts, or bearing evidence by chipping or gnawing of manipulation by 

 man in a recent state ; besides which they have sometimes been found in a highly-fossilized or 

 mineralized condition, unlike the bones of the smaller species, which contain much organic 

 matter and often look perfectly fresh. I am of opinion that the larger forms are the more 



*Lord Kelvin, the late President of the Eoyal Society, after thanking me for a copy of my paper, wrote : " You and 

 the geologists must, however, be satisfied with twenty million years for the earth's age. The 306 million years for the 

 denudation of the Weald in Kent, given as part of his foundation in the first edition of ' The Origin of Species,' was 

 dropped by Darwin himself after I showed it to be inconsistent with dynamics, and I think you will not find it in the 

 third or later editions. The 270 million years ' since the Cambrian period,' which you quote from Lyell, is utterly 

 untenable. He supported his assumption of infinite past time for geology by a thermo-electric invention of a perpetual 

 motion as good as many of the million 'perpetual motions ' that have been invented by ingenious persons who have not 

 learned dynamics or physics." A sufficient length of time was my postulate; and twenty million years suits my 

 argument quite as well as the more extended period. 



