X PREFACE 



realise intentions in this respect. Tlie scope and utility 

 of the work has been limited to a regrettable extent by 

 the absence of this provision, and more particularly on 

 the economic side. 



My acknowledgments for assistance rendered must of 

 necessity be incomplete. In the first place, my thanks 

 are due to the Khedivial Agricultural Society, which for six 

 years gave me freedom to conduct researches as I choose ; 

 for this exceptional treatment I am indebted to H.H. 

 Prince Hussein Pasha Kamel, President of the Society, to 

 Mr. G. P. Foaden, and to Abdel Hamid Bey Abaza, 

 successively Secretary-General thereof, while my colleagues 

 on the stafl" have given every assistance. Since my 

 transfer to the new Department of Agriculture the work 

 has been continued, the Mendel ian laboratory projected by 

 the Society has been established by the Egyptian Govern- 

 ment, and a pure-strain system of seed-supply is in process 

 of adoption. 



Many of the records utilised would not have been 

 obtainable without the steady co-operation after 1909 of 

 my assistant, Mr. Francis S. Holton, to whom I am 

 especially indebted. The members of the Cairo Scientific 

 Society, and of the Botany School at Cambridge have 

 displayed an encouraging interest in the work. 



To specify individual assistance among so many would 

 be invidious, but on looking back over the train of ideas 

 involved, I find that the most illuminating of these have 

 come from the late Mr. J. R. Gibson, English Com- 

 missioner for the State Domains, from Mr. F. F. Blackman, 

 F.R.S., Reader in Botany in the University of Cambridge, 

 and from Mr. J. A. Todd, Professor of Economics at the 

 Khedivial School of Law, Cairo, while the data on the 



