These travel on with the migrant people; some are dropped, others are preserved because of utility, sentiment or mere habit.

For centuries after the settlement of the Jews in Palestine, traces of their pastoral life in the grasslands of Mesopotamia could be discerned in their social and political organization, in their ritual and literature.

Survivals of their nomadic life in Asiatic steppes still persist among the Turks of Europe, after six centuries of sedentary life in the best agricultural land of the Balkan Peninsula.

One of these appears in their choice of meat.

They eat chiefly sheep and goats, beef very rarely, and swine not at all.[29] The first two thrive on poor pastures and travel well, so that they are admirably adapted to nomadic life in arid lands; the last two, far less so, but on the other hand are the regular concomitant of agricultural life.