GRAZING RESOURCES 181 
climatic pattern of today. The efficiency of the rainfall has, how- 
ever, been greatly reduced owing to the deterioration of the vege- 
tative cover and the increased evaporation from the soil surface, 
unprotected from the sun’s rays; the temperature, velocity, and 
sandload of the searing desert winds which blow over these 
denuded areas have a serious effect on the remaining vegetation, 
crops and trees, and effectively inhibit or retard regeneration. 
Although it may be a desirable objective to attempt to regen- 
erate some type of vegetation on all semi-arid lands, attention 
must obviously be directed first to those regions in which it is 
possible to carry out practical, and, as far as possible, economic 
measures within a reasonable period of time. The delineation of 
such areas would have to bear some relation to the amount and 
seasonal distribution of rainfall, the incidence of drought years, 
the present stage of deterioration, and other factors. In defining 
the area for immediate operations, it will be necessary to consider 
current forms of land use, the grazing systems on the desert and 
semi-desert lands, the extent of the practice of the cereal-fallow 
rotation in systems of shifting and settled agriculture, and the 
lower limits of rainfall efficiency at which simple systems of rota- 
tions of crops or reforestation are practicable. 
Throughout the semi-arid lands of the Mediterranean, the Near 
East, and India are to be found many types of rural sociology, 
village or tribal structure, religious belief and prejudice, and 
methods of crop and animal husbandry, but perhaps the outstand- 
ing factor which has to be considered, and which has played a more 
important part in the destruction of the vegetation, the prevention 
of its regeneration, and the increase of desiccation, is the socio- 
logical distinction between the shepherd and the cultivator. One 
writer in another part of the world has related this distinction to 
the patrilineal and matrilineal types of family structure and in- 
heritance. The shepherd has for centuries been a freedom-loving 
nomadic type, owning no land and having no interest in the prac- 
tice of proper land use for the sake of his village, tribe, or nation. 
The cultivator is the sedentary type, satisfied with the land around 
his home. Both have destroyed the vegetative cover for their 
separate purposes. As populations and livestock numbers have 
