To this Danish illustrative case it may of course be objected, and with some apparent reason, that these plants and animals which begin to come in evidence in a state of domestication in the kitchen middens, and which presently afforded the chief means of life to the later stone-age population, were introduced in a domestic state from outside; and that this technological gain was the product of another and higher culture than that into which they were thus intruded. The objection will have what force it may; the facts are no doubt substantially as set forth. However, the domestication and use of these races of plants and animals embodied no less considerable a workmanlike mastery of its technological problem wherever it was worked out, whether in Denmark--as is at least highly improbable--or in Turkestan, as may well have been the case. And the successful introduction of tillage and cattle-breeding among the kitchen-midden peoples from a higher culture, without the concomitant introduction of a corresponding gain in the mechanic arts from the same source, leaves the force of the argument about as it would be in the absence of this objection. The comparative difficulty of acquiring the mechanic arts, as compared with the arts of husbandry, would appear in much the same light whether it were shown in the relatively slow acquirement of these arts through a home growth of technological mastery or in the relatively tardy and inept borrowing of them from outside. So far as bears on the present question, much the same habits of mind take effect in the acquirement of such a technological gain whether it takes place by home growth or by borrowing from without. In either case the point is that the peoples of the kitchen-middens appear to have been less able to learn the use of serviceable mechanical expedients than to acquire the technology of tillage and cattle-breeding. The appearance of tillage and cattle-breeding (“mixed farming”) at this period of Danish prehistory, without the concomitant appearance of anything like a similar technological gain in the mechanic arts, argues either (_a_) that in the culture from which husbandry was ultimately borrowed and in which the domestication was achieved there was no similarly substantial gain made in the mechanic arts at the same time, so that this culture from which the crop plants and animals originally came into the North of Europe had no corresponding mechanical gain to offer along with husbandry; or (_b_) that the kitchen-midden peoples, and the other peoples through whose hands the arts of husbandry passed on their way to the North, were unable to profit in a like degree by what was offered them in the primary mechanic arts. The known evidence seems to say that the visible retardation in the mechanic arts, as compared with husbandry, in prehistoric Denmark was due partly to the one, partly to the other of these difficulties.