BOOKS AND CURRENT LITERATURE 



How TO Know the Mosses. — Mrs. Dunham's book, How to Know 

 the Mosses^ aims "to present mosses in a simple, non-technical way, 

 so that the student may recognize at least their genera and in some 

 cases their species without depending upon the use of a lens." This 

 book is in some respects unique and in the mind of the reviewer it 

 represents about as nearly the ideal as can be hoped for in dealing with 

 a fairly difficult group of small plants. 



The book has resulted from the work of several years in trying to 

 get usable keys not requiring a lens, and the author has not hesitated 

 to enlist the services of friends and co-workers in the preparation and 

 testing of such keys. It contains 287 pages, is attractively printed, 

 and is well illustrated by six full-page plates and 115 text figures, the 

 illustrations being line-drawings by the author, mostly in natural size. 

 The book contains the following headings: Abbreviations of Names 

 of Authors; Introduction, Habit and Manner of Growth, Leaves, Cap- 

 sules, The Keys Explained, How To Use the Keys; Helpful Suggestions, 

 Key to Distinguish Mosses from Common Hepatics and Lichens, Leaf 

 Key to Genera, Capsule Key to Genera, List of Genera. Then comes 

 the descriptive part of the work (pages 73-257) , and the book ends with 

 Helps to Identification of the Most Common and Conspicuous Mosses, 

 Glossary, and Index. 



In using the key one first traces the plant through the leaf key by 

 characters such as habitat, length of stem, shape of leaves, etc., this 

 leading to one or more numbers referring to genera treated in the text, 

 to which one turns for further distinctions or verifications. By using 

 the capsule key, constructed similarly to the leaf key, another series 

 of reference numbers is obtained and, by elimination of the nmnbers 

 not obtained by the use of both leaf key and capsule key, the list of 

 genera to be referred to in the text is often considerably reduced, or 

 even narrowed to one. The keys are uniform in treatment and easy 

 to work. 



^Dunham, Elizabeth Marie, How to Know the Mosses. Houghton, MiflBin 

 Company, Boston and New York, 1916 ($1.25). 



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