'What a fungus does. ,how it does it. ..and why..."

THE FUNGIAn Introduction to their Structure,

Classification, Activities, and Natural Economy

By FREDERICK A. WOLF, Professor of Botany, Duke Uni-versity, and FREDERICK T. WOLF, Assistant Professor ofBotany, Vanderbilt University.

Volume I of this reference textbook presents a thorough analysis of the develop-mental morphology and taxonomy of fungi. Volume II, representing a newt andimportant emphasis, is devoted specifically to the activities of fungi and theirrelation to man's welfare. Teachers will find the two volumes excellently plannedfor use in full-year advanced undergraduate and graduate courses on the nature offungi and their activities. The emphasis on problems relating to fungus activitiesshould also prove of interest and value to students majoring in plant pathology,microbiology, forestry, and agriculture.

The authors have followed the pedagogically sound procedure of first emphasiz-ing principles and then giving the illustrative material necessary to clarify the factsinvolved in that principle. They have omitted certain little known families, havede-emphasized phylogeny, and have arbitrarily given no consideration to lichens.

Both volumes are beautifully illustrated. All explanations are given in thelegends, so that illustrations and legends supplement the text, aiding in definingterms and in providing an understanding of the general morphology of typicalgenera or species.

Volume I-Published in June.438 pages 51 by 81 $6.00

Volume II-Published in July.538 pages 51 by 81 $6.50

John Wiley & Sons, Inc., 440-4th Ave., New York 16, N.Y.

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Mathematical

ByRUDOLPH K. LUNEBURG

FOLLOWING Ames's thesis that

visual sensations are related to out-

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By empirical investigation of the ap-

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ual space is not Euclidean, but is rep-

resented by the hyperbolic geometry

of Lobachevski. Published for the

Dartmouth Eye Institute.

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INTRODUCTION TO PALEOBOTANY

By CHESTER A. ARNOLD, University of Michigan. McGraw-Hill Publications in the BotanicalSciences. 448 pages, $5.50This up-to-date, comprehensive text, the first to be publshed on the subject in many years, is de-signed for graduate students and advanced undergradU~i- iI ot"' and biology. The approach isbotanical rather than geological, and the material is o.' *-...-: v around the large plant groups. Thenumerous illustrations are of superior quality and interest.

THEORY AND APPLICATIONS OF ELECTRICITY AND MAGNETISM

By CHARLES A. CULVER, Consulting Engineer; formerly of Carleton College. 594 pages, $5.00Serves as a basis for advanced study in theoretical physics, chemistry, and electrical engineering.In the chapter on radioactivity and atomic structure the material includes a treatment of the elemen-tary theory of the betratron and nuclear fission.

PHYSICAL CHEMISTRY

By the late E. D. EASTMAN; and G. K. ROLLEFSON, University of California. International ChemicalSeries. 525 pages, $4.50A rigorous presentation of the principles of physical chemistry for third- or fourth-year collegestudents. More advanced subject matter is included than is usual in a book of this size. Especiallynotable are the chapters on atomic structure, radioactivity and nuclear structure, and the crystalline5tate.

HISTORICAL GEOLOGY. New second edition

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MECHANICS. International Series in Pure and Applied Physics. 301 pages,$4.00

ELECTROMAGNETISM. International Series in Pure and Applied Physics. 245 pages, $3.50

By J. C. SLATER and NATHANIEL H. FRANK, Massachusetts Institute of Technology.Derived from the authors' well-known Introduction to Theoretical Physics. The material has beenrearranged and modified in such a way that each of the volumes is suitable for a term's course. Ex-planations have been expanded, and new material, illustrative examples, and problems have beenadded.

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Applications are invited for associate professorship in bacteriology and bac-teriologist Agriculture Experiment Station. West Virginia University,Address J. G. Leach, West Virginia University, Morgantown, W. Va.

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TRITTEN BY FOURMEN who are widely experienced in their field, and eachof whom is a specialist in the agriculture of a particular section of the UnitedStates, this new college text provides a highly practical study of the economic andtechnical problems of farm management. It covers all questions of managementwhich face the modem farmer-the organizing, operating, renting, and financing offarms; the buying of equipment; the selling of products; the hiring and manage-ment of labor, etc.-and combines these with the principles and facts of soilscience, agronomy, feeds and feeding, horticulture, and animal, dairy, and poultryhusbandry to show how they can best be used to achieve a profitable and smoothlyrunning farm. The text is broad enough to cover farming in all of the UnitedStates, and thorough enough to show the application of principles for the successfulmanagement of farms in every part of the country. It gives concrete examples ofall the main types of farming, from the simplest to the most complex.

PublishedJune 10th 1073 pages, illkstrated $5.50

John D. Black is Henry Lee Professor of Economics at Harvard University. Marion Clawsonis Regional Administrator, Western Division, Bureau of Land Management, U. S. Dept. of In-terior. Charles R. Sayre is Agricultural Economist, Bureau of Agricultural Economics, U. S.Dept. of Agriculture, and Superintendent of the Delta Experiment Station, Stoneville, Miss.Walter W. Wilcox is Professor of Agricultural Economics at the University of Wisconsin.

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