Mr Darwin's interest was excited by the evidences everywhere present of the immensity of this extinct population. "The number of the remains imbedded in the great estuary-deposit which forms the Pampas, and covers the gigantic rocks of Banda Oriental, must be extraordinarily great. I believe a straight line drawn in any direction through the Pampas would cut through some skeleton or bones.... We may suppose that the whole area of the Pampas is one wide sepulchre of these extinct gigantic quadrupeds."[15]
The whole plain of South America from the Rio Plata to the Straits of Magellan has been raised from the sea within the species-life of the existing sea-shells, the old and weathered specimens of which, left on the surface of the plain, still partially retain their colours! Darwin infers, as certain, from data which he has adduced, that the Macrauchen, that strange giraffe-necked pachyderm, lived long after the sea was inhabited by its present shells, and when the vegetation of the land could not have been other than it is now. And if the Macrauchen, then the Toxodon, the Scelidothere, the Megathere, the Mylodon, the Glyptodon, the Glossothere, and all the rest of the quaint but mighty host of gone giants, that once thronged these austral plains.
Evidence for the recent existence of the colossal ostrich-like birds of New Zealand is stronger still. It is about twenty-one years since the first intimation was given to scientific Europe of the remains of such animals, through some bones sent by the Rev. W. Williams to Dr Buckland. From these, and a collection soon afterwards sent home, Professor Owen established the genus Dinornis, identifying five species, the largest of which, D. giganteus, he concluded to have stood about ten feet in height. The remains have since been obtained in great profusion, and the result of further investigations by the Professor has been the establishment of three other genera, viz., Palapteryx, Nestor, and Notornis,—the latter a large bird allied to the Rails and Coots.
A very interesting communication from Mr Williams accompanied one of the consignments, extracts of which I will quote. It bears date "Poverty Bay, New Zealand, 17th May 1842." "It is about three years ago, on paying a visit to this coast, south of the East Cape, that the natives told me of some extraordinary monster, which they said was in existence in an inaccessible cavern on the side of a hill near the river Wairoa; and they shewed me at the same time some fragments of bone taken out of the beds of rivers, which they said belonged to this creature, to which they gave the name of Moa. When I came to reside in this neighbourhood I heard the same story a little enlarged; for it was said that this creature was still existing at the said hill, of which the name is Wakapunake, and that it is guarded by a reptile of the Lizard species, but I could not learn that any of the present generation had seen it. I still considered the whole as an idle fable, but offered a large reward to any who would catch me either the bird or its protector." These offers procured the collection of a considerable number of fossil bones, on which Mr Williams makes the following observations:—
"1. None of these bones have been found on the dry land, but are all of them from the banks and beds of fresh-water rivers, buried only a little distance in the mud.... All the streams are in immediate connexion with hills of some altitude.
"2. This bird was in existence here at no very distant time, though not in the memory of any of the inhabitants: for the bones are found in the beds of the present streams, and do not appear to have been brought into their present situation by the action of any violent rush of waters.
"3. They existed in considerable numbers,—(an observation which has since been abundantly confirmed.)
"4. It may be inferred that this bird was long-lived, and that it was many years before it attained its full size. (The writer grounds this inference on the disparity in dimensions of the corresponding bones, supposing that they all belonged to one and the same species; which, however, was an erroneous assumption.)
"5. The greatest height of the bird was probably not less than fourteen or sixteen feet. The leg-bones now sent give the height of six feet to the root of the tail.
"Within the last few days I have obtained a piece of information worthy of notice. Happening to speak to an American about these bones, he told me that the bird is still in existence in the neighbourhood of Cloudy Bay, in Cook's Straits. He said that the natives there had mentioned to an Englishman belonging to a whaling party, that there was a bird of extraordinary size to be seen only at night, on the side of a hill near the place, and that he, with a native and a second Englishman, went to the spot; that, after waiting some time, they saw the creature at a little distance, which they describe as being about fourteen or sixteen feet high. One of the men proposed to go nearer and shoot, but his companion was so exceedingly terrified, or perhaps both of them, that they were satisfied with looking at the bird, when, after a little time, it took the alarm, and strode off up the side of the mountain.