206 Scientific Intelligence. 



Stevens' earlier book, " Diseases of Economic Plants," lays espe- 

 cial emphasis on the host in its ti-eatment of the various diseases, 

 dealing with the symptoms of the disease, prevalence, damage 

 caused, methods of control, etc. ; the present work is more or less 

 complementary to this, in that it treats especially of the causal 

 organisms. 



After a brief introduction, the first part is devoted to the Myxo- 

 mycetes and Bacteria, and Phycomycetes, Ascomycetes, Basidio- 

 mycetes and Fungi Imperfecti follow on in the order named. All 

 genera and species of economic importance in this country, and a 

 few so far known only in Europe, are included. Each genus of 

 pathological importance is represented by at least one figure. 

 Practical keys for the various groups of fungi are supplied 

 throughout the book. 



One of the most commendable points is the comprehensive bib- 

 liography appended after each part. Such references to the litera- 

 ture are particularly helpful to the student engaged in research, and 

 as one looks through the book, the large number of fungi which are 

 said to be " probably," or "perhaps" parasitic, or of which little 

 seems to be known save the bare fact of their occurrence on a 

 given host, is certainly convincing as to the great need of such 

 research. 



In addition to the bibliographies, lists of the more useful gen- 

 eral works and periodicals, and a glossary and index are added. 

 A few typographical errors appear here and there, and also some 

 inconsistencies in the headings and bibliographical references; 

 yet the book represents such a vast amount of labor and is so 

 exceedingly valuable to students of plant pathology that we are 

 loath to mention these imperfections at all. a. h. g. 



4. Measures of Proper Motion Stars made with the 40-inch 

 Refractor of the Yerkes Observatory in the Years 1907 to 1912; 

 by S. W. Burnham. (Carnegie Institution of Washington, Publi- 

 cation 168.) — As one examines this record of a great contribution 

 to an important branch of astronomical research, it is natural to 

 contrast it with the earliest work of the same observer, done with- 

 out any previous training with the simplest instruments in such 

 fragments of time as could be saved from the business of a reporter 

 for the courts of Chicago, but stamped, then as now, with the mark 

 of an unequaled ability for observations of this kind. It need 

 hardly be said that with the best telescope in the world, the best 

 atmospheric conditions, and all the appliances of a great observa- 

 tory at command, Mr. Burnham's work cannot, be rivalled else- 

 where. 



The present volume, No. II, records about 9500 measurements, 

 following vol. I, which covered the period from 1897 to 1906, 

 published in the general Catalogue of Double Stars of the Carne- 

 gie Institution. The greater number of stars given in this volume 

 are taken from the same volume. Stars of appreciable proper 

 motion being in general our nearest group of neighbors, astro- 

 nomically speaking, as well as fairly bright for the same cause, 



