CONTENTS 
PAGE 
PREFACE . 4 2 ; : : F Vv 
INTRODUCTION . : ; : . ; . Xi 
GENERAL PART 
CHAPTER I 
THE Lire-History or Pvecinia Caricis, THE NETTLE AND SEDGE 
Rost : ‘ j ‘ . : i j : 1 
CHAPTER II 
THE SEXUALITY OF THE UREDINALES—THE NATURE OF THE 
SPERMATIA—NUCLEAR DIVISION IN THE UREDINALES—THE 
ALTERNATION OF GENERATIONS “4 F ; : 17 
CHAPTER III 
SPORE-FORMS OF THE UREDINALES—-GROUPING ACCORDING TO SPORE- 
FORMS ; , ‘ : 30 
CHAPTER IV 
Lire-Historizs OF OTHER UREDINALES—Pucernra Grawixis—P. 
Poarum—P. MaLvackarumM—GYMNOSPORANGIUM CLAVARLE- 
ForMmME—FEwpopuH¥LLum SEMPERVIVI—CRONARTIUM RIBICOLA— 
MELAMPSORA PINITORQUA—CALYPTOSPORA GOEPPERTIANA. 41 
CHAPTER V 
SPECIALISATION—IMMUNITY ‘i ‘ : . . . 62 
CHAPTER VI 
CLASSIFICATION—-PHYLOGENY . 3 73 
Note on MANIPULATION . ‘ { z 84 
