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. 



