CONTENTS 



Page 



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The geography of deserts. By Professor Frank Debenham, O.B.E. ... 1 



The physical aspects of dry deserts. By Brigadier R. A. Bagnold, F.R.S. 7 



Availability of under- ground water in hot deserts. By Professor F. W. 



OIl(J lLOII ••• ••• ••• ••• ••• »*• ••• ••• ••• •■• ••• ••« ••• ^ J 



Some bioclimatic observations in the Egyptian desert. By Dr C. B. 



■V 1 X -^ X aI Ho*** ••• ••• •«• ••• ••• ••• ••• ••« ••• ••• ••• ••• XO 



Plant ecological problems in increasing the productivity of arid areas. 



By Dr H. Boyko 28 



Modes 'contracte' et 'diffus* de la vegetation saharienne. By Professor 



X lla iVit_/llVJU ••• ••• ••• ••• ••• ••• ••• ••• ••• ••• ••• ••• J^ 



The Bahrain Islands and their desert flora. By Professor R. D'O. Good 45 



Hydro- economical types in the vegetation of Near East deserts. By 



Professor M. Zohary 56 



The occurrence of plant diseases in arid climates and their agricultural 



significance. By Professor I. Reichert 68 



Phytosociologie et mise en valeur des sols en Afrique du nord. By Pro- 

 fessor L. Emberger , 76 



Les relations entre les zones desertiques et la pullulation des parasites 

 des plantes. By Professor P. E. L. Vayssiere 



The desert locust and its environment. By Dr B.P.Uvarov, C.M.G., F.R.S. 85 



Sur I'origine et le developpement des insectes nuisibles aux plantes 



cultivees dans les oasis du Sahara francais. By Dr A.S. Balachowsky 90 



Role des insectes sociaux dans les terrains du Sahara. By Professor 



X^ • X-/ vT X 1 1 Q.X KJ. ••• ••• •■■ ••• ••• ••• ••• ••• ••« ••• >•• ••• XV/t 



The microbiological formation of sulphur in Cyrenaican lakes. By K.R. 



Butlin and J. R. Postgate 112 



Forests, Aridity and Deserts. By Professor E.P.Stebbing ... ... ... 123 



The influence of climatic factors on the reaction of desert shrubs to 



grazing by oheep. By Professor H. C. Trumble and K. Woodroffe 129 



Biological research and the productive transformation of steppe and 



desert in the Soviet Union. By Dr S. M. Manton, F.R.S 148 



Aspects of the ecology and productivity of some of the more arid regions 



of southern and eastern Africa. By Professor J.Phillips, F.R.S.E. 156 



Problems of physiology and ecology of desert animals. By Professor 



F. S. Bodenheimer 162 



80 



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