The gavial of the Ganges is reported to be a fish-eater only, and is considered harmless to man. The Indian museums, however, have large specimens, which are said to have been captured after they had destroyed several human beings; and so we may imagine that this structurally herbivorous lizard (the Megalania having a horny edentate upper jaw) may have occasionally varied his diet, and have proved an importunate neighbour to aboriginal encampments in which toothsome children abounded, and that it may, in fact, have been one of the sources from which the myth of the Bunyip, of which I shall speak hereafter, has been derived.
CHAPTER III.
ANTIQUITY OF MAN.
I do not propose to bestow any large amount of space upon the enumeration of the palæontological evidence of the antiquity of man. The works of the various eminent authors who have devoted themselves to the special consideration of this subject exhaust all that can be said upon it with our present data, and to these I must refer the reader who is desirous of acquainting himself critically with its details, confining myself to a few general statements based on these labours.
In the early days of geological science when observers were few, great groups of strata were arranged under an artificial classification, which, while it has lost to a certain extent the specific value which it then assumed to possess, is still retained for purposes of convenient reference. Masters of the science acquired, so to say, a possessive interest in certain regions of it, and the names of Sedgwick, Murchison, Jukes, Phillips, Lyell, and others became, and will remain, inseparably associated with the history of those great divisions of the materials of the earth’s crust, which, under the names of the Cambrian, Silurian, Devonian, Carboniferous, and Tertiary formations, have become familiar to us.
In those days, when observations were limited to a comparatively small area, the lines separating most of these formations were supposed to be hard and definite; forms of life which characterized one, were presumed to have become entirely extinct before the inauguration of those which succeeded them, and breaks in the stratigraphical succession appeared to justify the opinion, held by a large and influential section, that great cataclysms or catastrophes had marked the time when one age or formation terminated and another commenced to succeed it.
By degrees, and with the increase of observers, both in England and in every portion of the world, modifications of these views obtained; passage beds were discovered, connecting by insensible gradations formations which had hitherto been supposed to present the most abrupt separations; transitional forms of life connecting them were unearthed; and an opinion was advanced, and steadily confirmed, which at the present day it is probable no one would be found to dispute, that not all in one place or country, but discoverable in some part or other of the world, a perfect sequence exists, from the very earliest formations of which we have any cognizance, up to the alluvial and marine deposits in process of formation at the present day.[71]
Correlatively it was deduced that the same phenomena of nature have been in action since the earliest period when organic existence can be affirmed. The gradual degradation of pre-existing continents by normal destructive agencies, the upheaval and subsidence of large areas, the effusion from volcanic vents, into the air or sea, of ashes and lavas, the action of frost and ice, of heat, rain, and sunshine—all these have acted in the past as they are still acting before our eyes.