But this is only one part of the distribution of the garden-culture. Far north along the Atlantic seaboard, and as far inland as the mild Atlantic climate is perceptible, the same type prevails. Its ancient limit is traced meteorologically in Tacitus' complaints (for example) of the austerity of the lands beyond the Rhine. In this northern region grain crops pass from red to white wheat, from barley to oats, and from both to rye. The ease with which the Muskogean potato and tomato have been acclimatized, and their respective prevalence now in the Atlantic and Mediterranean sections, illustrate exactly the place which primitive hoe-culture held in the economy of the Old-World region. Early monuments of this culture, in which hoe and ox-plough are equally conspicuous, are the 'meraviglie' rock-carvings above Ventimiglia.[10] The fine flower of it is the Minoan civilization of the Crete and the South Aegean. Egyptian agriculture is also in great part hoe-work. South-eastward, outside the Carpathians, and within them also, in the great plain of Hungary, we meet a totally different regime; vast featureless and treeless grasslands, extending past the Black Sea and Caspian to the foot of the mountains of North Persia and the spurs of the Central Asian highlands. Here, if Man is to maintain himself at all, he must be master of tame animals which can eat the grass, and in turn sustain him. South of the eastward continuation of the woodland Mountain Zone, through Asia Minor into Persia, and also south of the Mediterranean lake-region and the ridges of Syria and the 'Africa Minor' of Tunis, Algeria, and Morocco, which partly enclose it, lies another group of grasslands, Arabia and Sahara, desert-hearted, but capable of sustaining a considerable population of nomad pastoral folk round their margins and in oases, and of emitting them in volcanic emigrations now and then.