viii THE WHEAT PLANT 



cultivated forms. This section of the work is based upon a prolonged 

 study of the living plants, forming what may be termed the Reading 

 Collection. The latter, which is grown annually at the University College 

 Farm, is probably the most representative collection in existence, and 

 includes all the races of wheats numbering nearly two thousand forms 

 derived from almost all wheat-growing regions of the world. 



For assistance in obtaining these I am especially indebted to the 

 Ministry of Agriculture and Fisheries and the Foreign Office ; to Dr. 

 Regel and M. C. Flaksberger of Petrograd and Dr. Vavilov of Moscow 

 for Russian and Central Asiatic wheats ; Professor Kozai, Tokio, for 

 Japanese wheats ; H. M. Leake, Esq., Economic Botanist to the Govern- 

 ment of the United Provinces, and D. Milne, Esq., Economic Botanist, 

 Punjab, for Indian wheats ; and numerous workers in other countries. 



I desire also to express my thanks to the Council of the College for the 

 provision of facilities for research ; to Miss Mason and Mr. F/O. Mosley 

 for assistance with experimental work ; and to Professor Pennington for 

 his enthusiastic interest in the wheat collection and the cultivation and 

 testing of selected forms. 



To Miss Erith, Lecturer in Agricultural Botany, I owe a debt of 

 gratitude for faithful assistance with records and experimental investiga- 

 tions during the last three years, and for the onerous task of proof-reading. 



All the illustrations are original, those of the ears of the various races 

 of wheat being natural size. 



JOHN PERCIVAL. 



UNIVERSITY COLLEGE, READING. 



