AGRTOULTURAT. BOTANY. 529 



As a result of his experiuieiits, the author found that for the lower plants 

 phytiu is a readily assimilable source of phosphorus, aud as it appears to modify 

 the production of diastases, toxins, pigments, etc., he thinks that it would in- 

 fluence the formation of chloroleucites and the progress of starch production. 



Lectures on plant physiology, L. Jost, trans, by R. J. 11. (Jikson {Oxford, 

 1907, pp. XIV+')6'i, figs. 112). — This is an authorized English translation of 

 Jost's Vorlesungeu iiber Pflanzenphysiologie, which appeared some three years 

 ago and which the author has brought up to the close of 1906. The original was 

 based upon a course of lectures at the University of Strassburg, and the trans- 

 lator has performed his work as literally as possible, without attempting to edit 

 the material in any way. E\ery chapter concludes with a bibliography of the 

 more recent and authoritative works relating to the subject treated. 



Plant physiology and ecology, F. E. Clements {yew York, 1907, pp. 

 XT +315, figs. 125). — The present text-book is based very largely on a previous 

 work by the author entitled Research Methods. The material has been rewrit- 

 ten aud rearranged into chapters, in which the plant is first considered as an 

 individual and then as a member of a plant group or formation. The book is 

 intended for use in classes in second-year botany in colleges and universities, 

 and it has been given two years' trial by the author with good results. 



Plant breeding, H. De Vries {Chicago and London, 1907, itp. XIII+360, 

 figs. 11 If). — This is a series of essays on plant breeding, with comments on the 

 work of the Svalof Station in Sweden and that of Luther Burbank in Cali- 

 fornia. As the work of Nils.son has only been published in Swedish and that 

 of Burbank has not yet been described by himself, the book will give an 

 authoritative account of the work of these two men in breeding agricultural 

 aud horticultural plants. The ^uthor regards the importance of the work of 

 Nilsson and Burbank as inestimable. These investigators and others have 

 shown the value of individual species which may be isolated by a single selec- 

 tion rather than by the more tedious aud less accurate method of improvement 

 by continuous selection. 



In addition to descri])tions of the methods and worlv of Xilsson, Hays, Bur- 

 bank, and others, chapters are devoted to evolution and mutation, corn breed- 

 ing, association of characters in plant lireefling, and the geographical distribu- 

 tion of plants as aft'ecting species. 



Studies in variation, G. Klebs {Arch. Entwickl. Alech. Organ., 2^ {1907), 

 \o. 1, pp. 29-113, figs. 15). — An account is gi^en of studies on Scdum spectabUe 

 in which the intluence of various factors on the number and arrangement of 

 leaves, number of flowers, and structure of floral organs is shown. A discus- 

 sion of the relation of environment to variation aud a bibliography complete 

 the paper. 



American root drugs, Alice Henkel {U. S. Dept. Agr., Bur. Plant Indus. 

 Bui. 107, pp. 80, pis. 7, figs. 25). — Descriptions are given of 50 drugs that are 

 found in the I'nited States, the list including the official root drugs as well as 

 many nonofiicial ones that are generally quoted in trade lists of the country. 

 Under each plant is- given the scientific aud pharmacoepial names, common 

 names, habitat, range, description of the plant and root, and information con- 

 cerning collection, prices, and uses. 



Seeds and plants imported during the period from December, 1905, to 

 July, 1906. Inventory No. 21 {U. 8. Drpt. Agr., Bur. Plant Indus. Bui. 

 106, pp. 125). — This inventory represents the accessions of the Office of Seed 

 and riant Introduction between December 15, 1905. and Julj 27. 1900. It con- 

 tains 2,2(>0 items, which were introduced for experimental purposes. Among the 

 more important collections are those of F, N. Meyer, agricultural explorer in 



