1890.] MICKOSCOPICAL JOUKNAL. 219 



NOTICES OF BOOKS. 



Structural and Systematic Botany. By D. H. Campbell, Ph. D. 

 12°, 253 pp. Ginn & Co., Boston. 



In the present volume Dr. Campbell has abandoned the too prev- 

 aleHt feature of existing text-books that the chief aim of botany is to 

 teach the ability to trace a plant by means of an analytical key, the 

 subject being exhausted as soon as the name is discovered, and, as a 

 substitute, advances the theory that the knowledge of the plant itself is 

 the object to be desired. In selecting the plants employed as examples 

 of the different groups, such were chosen, as far as possible, as were 

 everywhere common. 



The author thoroughly appreciates the value of the microscope in 

 botanical work, as he says, ^' though much can be done in the study of 

 plants without microscopic aid, other than a hand lens, for the thor- 

 ough understanding of the structure of any plant a good compound 

 microscope is indispensable." The volume, compiled as it is, cannot 

 fail to give the student a clear apprehension of the real aims of botan- 

 ical science, and is decidedly more than an " analysis" of flowers. 

 Best Elizabethan Plays. Edited by William R. Thayer. 12°, 61 1 pp. 

 Ginn & Co., Boston. (Price, $1.40.) 



The object of this volume is to present specimens of the best work 

 of five of the greatest Elizabethan dramatists who stand highest among 

 Shakespeare's contemporaries. The selection comprises the Jew of 

 Malta ; The Alchemist, by Ben Jonson ; Philaster, by Beaumont and 

 Fletcher; The Two Noble Kinsmen, by Fletcher and Shakespeare; 

 and the Duchess of Malfy, by Webster. The binding together of these 

 masterpieces enables the general reader as well as the college student 

 to taste of the quality of Shakespeare's rivals and thereby to esteem 

 more adequately Shakespeare himself. It thus furnishes not only the 

 best specimen of the dramatic works of each of the five Elizabethan 

 poets who rank next to Shakespeare, but also a general view of the 

 development of the English drama from its rise in Marlow to its last 

 strong expression in Webster. The author has adopted the explana- 

 tions of the best editors, supplementing them from his own researches 

 where it seemed necessary. The presence of the notes at the bottom 

 of each page, rather than at the end of the book, is a desirable feature. 

 Altogether it is a work equally well adapted to the library and to the 

 class-room, and indispensable to the student of English literature. 



Directional Calculus. By E. W. Hyde. 12°, 247 pp. Ginn & Co., 



Boston. (Price, $2.15.) 



Professor Hyde believes that the field is at last ripe, for the introduc- 

 tion of the comprehensive system of Multiple Algebra invented by 

 Herman Grassman and called by him Ausdehnungslehre or Theory 

 of Extension., though it was long neglected by the mathematicians 

 even of Germany ; and the present text-book, through which students 

 may become acquainted with the principles of the subject and its appli- 

 cation, was designed to introduce the system to the knowledge of the 

 coming generation of English-speaking mathematicians. 



To obviate the diflficulty which had been the main hindrance to the 

 general cultivation of Grassman's process, its too great generality, the 

 author has thought best to restrict the discussion to space of two and 



