LIST OF PLATES xv 
PLATE FACING PAGE 
XVIII. GALLS ON PINNULES OF BRACKEN - - - 130 
XIX. JUNIPER STEM GALLED BY GYMNOSPORANGIUM 
CL A VAR IA EFORME ... - 134 
From a photograph by Mr. Edward Step, F.I.S. 
xx. “witches’ brooms” on birch - - - 156 
From a photograph by Mr. Roger Hutchinson, M.R.C.S. 
XXL *GALLS CAUSED BY MITES ( ERIOPHYES ) - - 158 
XXII. *OAK LEAVES AND BUDS GALLED BY GALL-WASPS 
(GENUS DRYOPHANTA) - - - - 168 
XXIII. LEAVES OF WYCH-ELM GALLED BY OLIGOTROPHUS 
LEEMEI - - - - - - 176 
XXIV. POPPY-HEADS GALLED BY AULAX PAPAVERIS - 186 
XXV. BULLACE FRUITS GALLED BY EXOASCUS PR UNI - 196 
XXVI. BLACKBERRY STEMS GALLED BY CONIOTHYRIUM 
FUCKELII ------ 200 
XXVII. HEMLOCK WATER DROPWORT GALLED BY PROTO- 
MYCES MACROSPORUS - 222 
XXVIII. SMALL BINDWEED GALLED BY ERIOPHYES CON¬ 
VOLVULI ------ 226 
XXIX. *GALLS ON LONG-ROOTED CAT’S-EAR AND GROUND 
IVY ------- 228 
XXX. LEAVES OF MEALY GUELDER ROSE GALLED BY 
OLIGOTROPHUS SOL MS 11 - 238 
XXXI. COMMON MILFOIL GALLED BY RHOPALOMYIA 
MILLEFOLII ----- 242 
XXXII. LEAVES OF SOW-THISTLE GALLED BY CYSTIPHORA 
SONCHI ------ 250 
Note. — The line intended to serve as an index to 
the size of the i?isect is in all cases one-third in excess 
of the actual length. 
