314 THE JOURNAL OF BOTANY 



where the hypertrophy is caused by fungi. Most English works 

 on the subject have dealt principally with the zoological aspect 

 and have therefore not attracted the general run of botanists. 

 We should imagine that Mr. Swanton's book will appeal to such 

 as have no previous knowledge of the subject. The introduction 

 gives a short but interesting historical account of these " super- 

 crescences, productions, or excretions " ; a resume of Kerner's 

 arrangement of insect and fungus galls, based on their form and 

 general structure ; notes on collecting and preserving galls ; and a 

 synoptic table of the genera of animal and fungus gall-causers of 

 British plants. The interesting life-histories of the gall-causers 

 — sawflies, wasps, beetles, moths, flies, aphides, mites, eel-worms, 

 fungi, and Mycetozoa are then described and useful "economic 

 notes " are added. Then follows a classified and descriptive cata- 

 logue of plant-galls. The primary division is botanical, the 

 host-plants being arranged as in Engler's system ; the galls on 

 each are then tabulated according to the causative organism. 

 There are a number of explanatory text-figures and thirty-two 

 plates, half of which are coloured — the others mostly photo- 

 graphs. All the photographs are excellent. We think this could 

 also be said of the originals of the coloured plates, but some of 

 them have lost much in the printing. There is a useful bibliography 

 and a full index. The book is cheap, useful, and interesting. 



J.E. 



An Introduction to the Chemistry of Plant Products. By Paul 

 Haas, D.Sc, Ph.D., and T. G. Hill, F.L.S. 8vo, pp. xii, 401. 

 London : Longmans. 1913. Price 7s. 6d. net. 



Many of the problems of plant physiology require for solution 

 a combination of botanical and chemical methods. The present 

 work is an attempt to provide students of plant physiology with 

 an introductory account of the chemistry and biological signifi- 

 cance of some of the more important substances occurring in 

 plants. The substances are treated under the following sections : 

 (1) Fats, Oils, and Waxes, Phosphatides; (2) Carbohydrates; 

 (3) Glucosides ; (4) Tannins ; (5) Pigments ; (6) Nitrogen bases ; 

 (7) Colloids ; (8) Proteins ; (9) Enzymes. The subject-matter is 

 mainly chemical ; the classification, means of detection and quan- 

 titative estimation of the various substances are treated in detail, 

 but a valuable summary is also given of the facts relating to the 

 meaning of the substance in the life-history of the plant and its 

 method of formation. Special reference may be made to the 

 section on Proteins and those dealing with Enzymes, which should 

 be of considerable interest to the general student of botany. The 

 book fills a gap, and is a valuable contribution to botanical 

 literature. The subject-matter is well arranged, and there is a 

 useful index. 



A. B. P. 



