LIST OF PLATES 



Those in colour are marked with an asterisk 



PLATE FACING PAGE 



I. *THE OYSTER-GALL AND ITS INFLUENCE ON THE 



COLORATION OF OAK LEAVES 6 



II. *WILLOW LEAVES WITH GALLS CAUSED BY SAW- 

 FLIES - - - 22 



III. *GALLS ON LEAVES OF WILD ROSES - frontispiece 



IV. *THE OAK-APPLE AND ITS ALTERNATE FORM - 34 

 V. *OAK SPANGLE GALLS WITH THEIR ALTERNATE 



FORMS - - - - - 36 



VI. *GALLS CAUSED BY BEETLES,- - - - SO 



VII. *SOME GALL-CAUSING MOTHS, WITH THEIR GALLS- 56 



VIII. *GALLS CAUSED BY THE LARVAE OF FLIES (VARIOUS 



GENERA) - - - - - - 66 



IX. *GALLS CAUSED BY THE LARVAE OF FLIES (GENUS 



OLIGOTROPHUS) - - - - 70 



X. *CONCERNING CHERMES STROBILOBWS - - 82 

 XI. TUMOURS ON A BRANCH FROM AN APPLE TREE - 86 



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



XII. *GALLS ON LEAVES OF ASH AND POPLAR - - 88 



XIII. *MITE GALLS ON SYCAMORE AND MAPLE - • 98 



XIV. BEECH TRUNK GALLED BY MITES (?) - I04 



From a photograph by Mr. Sydney Webb. 



XV. EELWORM GALLS ON MILFOIL LEAVES IIO 



Reproduced from " British Vegetable Galls," by permission of 

 Messrs. Hutchinson and Co. 



XVI. *GALLS CAUSED BY FUNGI AND MYCETOZOA I16 



XVII. "WITCH'S BROOM", ON SPRUCE BRANCH I18 



From a photograph by Miss Truda Hutchinson. 



xiv 



