UNITED STATES DEPARTMENT OF AGRICULTURE 

 BULLETIN No. 183 



Contribotion from the Bureau of Plant Industry 

 WM. A. TAYLOR, Chief 



Washington, D. C. 



PROFESSIONAL PAPER 



April 13, 1915 



MORPHOLOGY OF THE 



BARLEY GRAIN WITH REFERENCE TO 



ITS ENZYM-SECRETING AREAS 



By 



ALBERT MANN, Plant Morphologist, and H. V. HARLAN, 

 Agronomist in Charge of Barley Inyestigations 



CONTENTS 



Introduction 



Structure of the Barley Grain . . . . 



Development of the Barley Grain . . . 



Germination 



Conversion of the Endosperm . . . . 



RSsumS of the Conclusions of Other In- 

 vestigators 



Source of DiaKtatic Ferments . . . . 



Location of Diastase Secretion . . . . 



Source of Cytatic and Proteolytic Fer- 

 ments 



Page 



Function of the Alenrone Layer .... 18 

 Greater Diastatic Power of Small-Berried 



and High-Nitrogen Barleys 19 



Efficiency of Conversion 21 



American Barleys 27 



Modifications Possible by Culture ... 28 



Foreign Barleys 30 



Summary 31 



WASHINGTON 



GOVERNMENT PRINTING OmCE 



191C 



