This chapter marks a transition in the volume from agriculture to other subsistence bases. It is concerned particularly with the effects of environment-and the technologies used to exploit it-on the culture and identity of pastoral nomadic groups, mining colonies, and certain agricultural communities specializing in different ranges of crops. It deals with an arid region where these three occupational categories are closely linked and interdependent economically. It suggests that before agricultural technology reached a stage of development that would allow exploitation of such a marginal region, exploitation by other means (for example, pastoralism) was not possible either, and excess population from the lush peripheries was not able to overflow into the deserts.