RESEARCH AND DEVELOPMENT 61 
long periods with limited water supply under conditions of ex- 
cessive insolation, very high day temperatures and low night 
temperatures. 
Animals 
Draz, Director of the Desert Range Development Project in 
Egypt, also referred to the need for a thorough understanding of 
the ecological, logical, genetic, and physiological bases which will 
enable the selection of plants and animals most suited to arid 
conditions, and drew attention to the importance in animals of 
heat tolerance and heat dissipation, about which much is still 
to be learned. He stressed the idea that it is short-sighted to look 
down on local breeds which have become adapted to the condi- 
tions of living in the environment (See p. 335). 
Man 
Whatever research work is done in any or all the fields we have 
so far considered, the end result should be for the benefit of man. 
It is appropriate, therefore, to think at this stage about man 
himself, his well-being and living conditions. One striking feature 
of man in the desert is his nomadism. While it may always be 
that some movement of flocks must occur to and from grazing 
areas, it does not follow that the shepherds remain nomads. 
It is unnecessary to do more than remember how very different 
the lives of men, women, and children are under nomadic condi- 
tions from those enjoyed in the dry climate of New Mexico. Any 
changes in modes of living must mean great social adjustments 
for those people. 
Ladell, Director of the Hot Physiological Research Unit in 
Nigeria, dealing with the influence of environment in arid regions 
(In a paper in press) points out the wide range in temperature 
which man has to live under, as for example at Basra where the 
mean monthly minimum varies from freezing to 83°F and the 
mean monthly maximum from 67° to 1og°F. Under these condi- 
tions there is also little cloud and scanty vegetative cover so that 
the ground radiates heat, and dust-laden air radiates still more. 
Add to this wind, and water loss from the body may proceed 
