.November 17, 1905.1 



SCIENCE. 



631 



microscopy for second year students in chem- 

 istry and biology at the Massachusetts Insti- 

 tute of Technology. The object of the course 

 is to give facility in the manipulation of the 

 microscope and an acquaintance with the 

 scope of its practical application. 



The first four chapters consider the micro- 

 scope and its accessories, and the other eight 

 chapters deal with the starches, adulterations 

 of food and drugs, textile fibers, paper, medi- 

 cine and sanitation, forensic microscopy, 

 microchemistry, petrology and metallurgy. 



Each subject is dealt with in a general 

 manner to give the student the principles and 

 the point of view. Exercises are then given 

 to illustrate th^. methods necessary for the 

 elucidation of the questions which arise in 

 actual practise. 



The book is well conceived and satisfac- 

 torily worked out. The statements are usu- 

 ally clear and concise. As planned by the 

 author, it is an introduction to the subject, 

 and was designed for use by a teacher pos- 

 sessing knowledge of the more elaborate books, 

 and the monographs bearing upon the various 

 subjects. Eor the student, excellent refer- 

 ences to good sources for further information 

 are given with each chapter so that those espe- 

 cially interested can follow out the subject. 



It is not particularly adapted for private 

 learners, as the directions are frequently too 

 brief without the supplementary instruction 

 which naturally goes with a laboratory course. 

 Two directions would prove unsatisfactory in 

 practise: On page 41 the student is told to 

 transfer cover-glasses from the potassium di- 

 chromate, sulfuric acid cleaning mixture to 

 fifty per cent, alcohol. After a thorough 

 rinsing in clean water, should have been 

 added. On page 28 under the directions for 

 using the Abbe condenser, it is said : ' In gen- 

 eral an opening [of the diaphragm] about the 

 size of the front lens of the objective will 

 yield good results.' While this applies to 

 lighting, when no condenser is used it would 

 lead one to light with a less aperture when 

 using an oil immersion objective than when 

 using a low power dry objective. It contra- 

 venes the principles given in the preceding 

 chapter. These and a few other slips will be 



easily remedied by the teacher and will be 

 naturally righted in a new edition. 



It is a source for congratulation that books 

 of this kind are originating from the labora- 

 tories of our country, and it is hoped that the 

 nimiber will increase. S. H. G. 



-The Structure and Development of Mosses 

 . and Ferns (Archegoniates) . By Douglas 

 Houghton Campbell, Ph.D., Professor of 

 Botany in the Leland Stanford Junior Uni- 

 versity. New York, The Macmillan Com- 

 pany; London, Macmillan & Co., Ltd. 1905. 

 All rights reserved. Pp. vii + 657. 8vo. 

 It is but a little more than ten years since 

 the first edition of this book appeared, and now 

 we have a second and considerably revised 

 edition, in which much new matter has been 

 added. By an odd oversight, the fact that this 

 is a second edition is not indicated on the 

 title page, although it is clearly stated in the 

 ' Preface to the Second Edition ' with which 

 the volume opens. In this revision, the whole 

 book has been printed from new type, none of 

 the old stereotype plates having been used. 

 This has given the author as miich freedom 

 in the preparation of the present book as 

 though it were wholly new, and he has not been 

 obliged to confine his changes to such as could 

 be made to conform to the limitations of the 

 old plates. The result is that this is a new 

 book, and while it resembles the earlier one, 

 and contains much matter which was in that 

 edition, there is scarcely a page or paragraph 

 in which the author has not made some 

 changes of greater or less importance. 



The new book follows the same general 

 sequence as the old one, and, on a cursory 

 glance, the reader sees little difference, yet a 

 closer examination shows many changes and 

 additions. The more important changes are 

 those in the treatment of Marattiales, 

 Isoetaceae and Lycopodinae. In the old edi- 

 tion, the Isoetaceae were discussed in connec- 

 tion with the Marattiales , to which they were 

 regarded as related, but in the new book we 

 find them taken ^^p after the Lycopodinae, be- 

 ing regarded as ' suificiently distinct to war- 

 rant the establishment of a separate order, 

 Isoetales.' 



