Natural History. 87 



ume 2. The present volume completes the dicotyledonous Angio- 

 sperms, extending from the Euphorbiaceae through the Corna- 

 ceae. Engler was assisted in the preparation of this work by 

 several of his friends and students, notably. Dr. Pax of Breslau, 

 who is responsible for the exhaustive treatment of the Euphor- 

 biaceae. Other collaborators include Drs. Brehmer, Brandt, 

 Burret, Diehls, Gilg, Harms, Krause, Loesener, Mildbraed, Radl- 

 kofer and Ulbrich. The method of treatment follows that of the 

 earlier volumes and is essentially similar to that of the familiar 

 Pflanzenreich. The discussion of the families is followed by a 

 summary of the geographical relations of the African flora with 

 examples of the various floristic elements of which it is com- 

 posed ; and also by an account of the morphology, taxonomy, dis- 

 tribution and origin of the characteristic xerophytes of the 

 country. a. f. hill. 



8. Precis de Physiologic Vegetale; by L. Maquenne. Pp. 

 175, with 4 text-figures. Paris, 1922 (Payot & Cie.). — Professor 

 Maquenne 's work gives in condensed form the essentials of plant 

 physiology. It represents a resume of a course of lectures 

 given for many years at the Natural History Museum in Paris. 

 The first chapter deals with certain physical and chemical 

 phenomena which have an immediate bearing on the plant's 

 activities. In the second chapter germination is discussed; in 

 the third, fourth and fifth, the anabolic processes of the plant ; 

 in the sixth, the respiratory processes; and in the seventh and 

 eighth, the movements of water and other substances in the plant, 

 together with the changes associated with maturity. The ninth 

 and last chapter discusses the more important chemical sub- 

 stances found in plants. a. w. e. 



9. The North American Slime-moulds: A descriptive list of 

 all species of Myxomyeetes hitherto reported from the continent 

 of North America with notes on some extra-limital species ; new 

 and revised edition; by Thomas H. Macbride. Pp. xvii, 299, 

 with 23 plates. New York, 1922 (The Macmillan Company). — 

 The first edition of this valuable manual was published in 1899 

 and contained 231 pages and 18 plates. The increase in size is 

 largely due to the addition of 53 species to the flora of North 

 America, including 12 proposed as new. The extra-limital 

 species described number 13 and occur in various parts of the 

 world. The most important change in the systematic portion 

 of the work is the recognition of both orders and families, these 

 groups being designated by the usual suffixes. In the first edition 

 the orders had the family suffix while the families had the tribal 

 suffix. The first 18 plates in the new edition are in large part 

 redrawn from those in the first edition, while the additional 

 plates illustrate the species since accredited to our flora. A com- 

 parison of the two editions demonstrates the continued activity of 



