PREFACE. 



For several years past it has been one of my favourite 

 pastimes to collect vegetable galls, and to observe the 

 many peculiarities connected with their growth. The 

 accumulation of a large number of specimens and a mass 

 of notes resulting from these researches has awakened 

 the desire to arrange them in book form. The purpose 

 of this volume is not to deal exhaustively with the 

 subject, but rather to afford the collector and the student 

 a medium of reference, whereby about two-thirds of the 

 number of vegetable galls at present discovered may be 

 determined. Complete lists of all known galls are also 

 given, with a brief description of each. The art of photo- 

 graphy has been employed to represent the specimens 

 as they appeared in a living condition. I have not 

 attempted to produce pretty pictures ; my endeavour has 

 been to arrange the specimens in such a manner that the 

 various distinctive features of the galls themselves may 

 be easily recognised. All the illustrations (except plate 

 i) are my own production. No illustrations are given 

 of the oak-galls. They will probably appear subsequently 

 in a volume devoted exclusively to oak-galls. In giving 

 the average dimensions of each gall, it has been con- 

 sidered advisable to employ the millimetre as the unit 

 (25 mm. =1 inch). 



Very much remains to be done in this section of 

 natural history, and it is hoped that the perusal of the 



