We know that from the life of hunting man passed into the pastoral stage, having learned to tame animals.  How he came to do so, and by what motives he was actuated, is still a mystery.  It may be, as M. Salomon Reinach has also suggested, that it was some curious and indefinable sense of kinship with them that led him to do so, or more probably, as the present writer thinks, some sense of a need of the alliance of animals against hostile spirits.  In all probability it was no motive which we can now fathom.  The mind of early man was like the unfathomable mind of a boy.  From the pastoral life again man passed after long ages into the life of agriculture, and the remains of neolithic man in Gaul and in Britain give us glimpses of his life as a farmer.  The ox, the sheep, the pig, the goat, and the dog were his domestic animals; he could grow wheat and flax, and could supplement the produce of his farm by means of hunting and fishing.  Neolithic man could spin and weave; he could obtain the necessary flint for his implements, which he made by chipping and polishing, and he could also make pottery of a rude variety.  In its essentials we have here the beginnings of the agricultural civilisation of man all the world over.  In life, neolithic man dwelt sometimes in pit-dwellings and sometimes in hut-circles, covered with a roof of branches supported by a central pole.  In death, he was buried with his kin in long mounds of earth called barrows, in chambered cairns and cromlechs or dolmens.  The latter usually consist of three standing stones covered by a cap-stone; forming the stony skeleton of a grave that has been exposed to view after the mound of earth that covered it has been washed away.  In their graves the dead were buried in a crouching attitude, and fresh burials were made as occasion required.  Sometimes the cromlech is double, and occasionally there is a hole in one of the stones, the significance of which is unknown, unless it may have been for the ingress and egress of souls.  Graves of the dolmen or cromlech type are found in all the countries of Western Europe, North Africa, and elsewhere, wherever stone suitable for the purpose abounds, and in this we have a striking illustration of the way in which lines of development in man’s material civilisation are sooner or later correlated to his geographical, geological, and other surroundings.  The religious ideas of man in neolithic times also came into correlation with the conditions of his development, and the uninterpreted stone circles and pillars of the world are a standing witness to the religious zeal of a mind that was haunted by stone.  Before proceeding to exemplify this thesis the subsequent trend of Celtic civilisation may be briefly sketched.