The very moderate pace of the technological advance in early times in the mechanic arts stands out more strikingly when it is contrasted with what was accomplished in those arts, or rather in those occupations, that have to do immediately with living matter. Some of the crop plants, for instance, and presently some of the domestic animals, make their appearance in Denmark late in the period of the kitchen middens; which falls in the early stone age of the Danish chronology, that is to say in the early part of the neolithic period as counted in terms of the European chronology at large. These, then, are improved breeds of plants and animals, very appreciably different from their wild ancestors, arguing not only a shrewd insight and consistent management in the breeding of these domesticated races but also a long continued and intelligent use of these items of technological equipment, during which the nature and uses of the plants and animals taken into domestication must have been sufficiently understood and taken advantage of, at the same time that a workmanlike selection and propagation of favourable variations was carried out. Some slight reflection on what is implied in the successful maintenance, use and improvement of several races of crop plants and domestic animals will throw that side of the material achievements of the kitchen-midden peoples into sufficiently high contrast with their chipped flint implements and the degree of mechanical insight and proficiency which these implements indicate.