There is another consideration also which must have greatly diminished the chance of finding human remains in Tertiary deposits. Why did men take to living in dark and damp caves? Presumably for protection against cold. But in the Miocene and the greater part of the Pliocene there was no great cold. The climate, as shown by the vegetation, was mild, equable, and ranged from semi-tropical to south-temperate, and the earth was to a certain extent covered by forests sustaining many fruit-bearing trees. Under such conditions men would have every inducement to live in the open air, and in or near forests where they could obtain food and shelter, rather than in caves. And a few scattered savages, thus living, would leave exceedingly few traces of their existence. If the pygmy races of Central Africa, or of the Andaman Islands, became extinct, the chances would be exceedingly small of a future geologist finding any of their stone implements, which alone would have a chance of surviving, dropped under secular accumulations of vegetable mould in a wide forest. It is the more important therefore where instances of human remains in Tertiary strata, supported by strong _primâ facie_ evidence, and vouched for by competent authorities, do actually occur, to examine them dispassionately, and not, as a good many of our English geologists are disposed to do, dismiss them with a sort of scientific _non possumus_, like that which was so long opposed to the existence of Quaternary man, and the discoveries of Boucher-de-Perthes. It is perfectly evident from the admitted existence of man throughout the Quaternary period, already spread over a great part of the earth's surface, and divided into distinct types, that if there is any truth in evolution, mankind must have had a long previous existence. The only other possible alternative would be the special miraculous creations of men of several different types, and in many different centres, at the particular period of time when the Tertiary was replaced by the Quaternary. In other words that, while all the rest of the animal creation have come into existence by evolution from ancestral types, man alone, and that not merely as regards his spiritual qualities, but physical man, with every bone and muscle having its counterpart in the other quadrumana, was an exception to this universal law, and sprang into existence spontaneously or by repeated acts of supernatural interference. As long as the account of the creation in Genesis was held to be a divinely-inspired narrative, and no facts contradicting it had been discovered, it is conceivable that such a theory might be held, but to admit evolution for Quaternary, and refuse to admit it for Tertiary man, is an extreme instance of "straining at a gnat and swallowing a camel," for a duration of even 10,000 or 20,000 years is just as inconsistent with Genesis as one of 100,000 or half a million.