THE WHEAT PLAXT 



187 



the new grain. It is well illustrated and full of interest. Part II 

 occupies tlie remainder of the book, and is devoted mainly to 

 classilication, com[)rising a detailed description of the different races, 

 varieties, and forms of cultivated wheat. Two wild species of wheat 

 are known: (I) Triticuni agilojyoide'S 13al., Wild Small Spelt, a 

 native of the Balkan Peninsula and Asia Minor, from which one 

 race of cultivated Avheat, T. monococcum, Small Spelt, has been 

 derived ; and (2) T. clicoccoides Korn., Wild Emmer, native of 

 Syria and Western Persia, under which Prof. Percival groups the 

 remaining ten cultivated races. The races are subdivided into 

 smaller groups or varieties, based upon obvious hereditary morpho- 

 logical differences of the ears and grain, and under each variety are 

 a number of forms, the grouping of which in some of the common 

 varieties offers considerable difficulty. In the remaining chapters the 

 author discusses tlie origin and relationships of the races of wheat, 

 variation, hybridisation, improvement and breeding, and yield. As 

 regards phylogenetic relationship, the author groups the races in 

 three series : I, the Small Spelt derived from T. monococcum ; 

 II, the cultivated Emmer Wheats, derived from T. dicoccoides and 

 including the Macaroni wheats {T. durum), Polish wheat {T. polo- 

 lu'cum), and rivet- or cone-wheats (T. furgidum) ; and III, the 

 Bread Wheats proper (T. vulgare), with which T. Spelta is closely 

 related ; these are regarded as derived from a crossing of T. dicoc- 

 coides and species of jEgilojis. An alphabetical list of wheats refers 

 each name to its race and variety, and indicates its country of origin. 

 A bibliography and index conclude the volume. The numerous plates 

 are well reproduced by photography, and are a valuable adjunct to 

 the text. Prof. Percival has fuUilled the hope expressed in his 

 preface, tliat this book may be a model of the research that is 

 needed upon farm plants. It should also act as a stimulus to 

 further effort. 



A. B. R. 



The Inteki^ational Potato Coxferexce. 



The Royal Horticultural Society has issued (85.), a Report, 

 edited b}^ Mr. W. R. Dykes, of the International Potato Conference 

 held jointly by the Ministry of Agriculture and Fisheries and the 

 Royal Horticultural Society in November last " in order to secure the 

 full discussion of the manifold and complex ])roblems with which 

 breeders and growers of potatos are confi-onted." The volume will 

 be useful to those who are interested in potato problems : it must 

 be said however that the contributions are of \qyj unequal merit ; a 

 few are valuable and give details of recent work, but others are 

 below the standard one is entitled to expect at an International 

 Conference. The lirst paper is on " Breeding, Selection and Develop- 

 ment Work in the U.S.A." by W. Stewart, followed by three papers 

 on the same aspects in Britain hj W. Robb, I). MacKelvie, and 

 F. J. Chittenden. H. V. Taylor "^writes on "The Industrial and 

 Commercial Uses of the Potato " ; R. N. Salaman has an able paper 

 on *' Degeneration of Potatoes," and collaborates with J. W. Lesley 



