LIST OF PLATES xv 



■"'■"'■''E PACIHG PAGE 



XVIII. GALLS ON PINNULES OF BRACKEN I30 



XIX. JUNIPER STEM GALLED BY GYMNOSPORANGIUM 



CLAVARIAEFORME I34 



From a photograph by Mr. Edward Step, F.I.S. 

 XX. "witches' BROOMS" ON BIRCH 1 56 



From a photograph by Mr. Roger Hutchinson, M.R.C.S. 

 XXI. *GALLS CAUSED BY MITES {ERIOPHYES) 1 58 



xxii. *oak leaves and buds galled by gall-wasps 



(genus drvophanta) 168 



xxiii. leaves of wych-elm galled by oligotrophus 



LEEMEI - - - 176 



XXIV. POPPY-HEADS GALLED BY A ULAX PAPA VERIS 1 86 



XXV. BULLACE FRUITS GALLED BY EXOASCUS PRUNI - 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 SOLMSII - - 238 



XXXI. COMMON MILFOIL GALLED BY RHOPALOMYIA 



MILLEFOLII - 242 



XXXH. LEAVES OF SOW-THISTLE GALLED BY CYSTIPHORA 



SONCHI - • - - 250 



Note. — The line intended to serve as an index to 

 the size of the insect is in all cases one-third in excess 

 of the actual length. 



