125 



book consists of the full page plates of excellent line drawings. 

 For Potamogeton there are fourteen plates illustrating thirty-three 

 species and thirteen varieties or forms. In the case of the willows, 

 where sixteen species are described, together with several varieties 

 and forms, there are keys accompanied by illustrations to plants 

 with mature leaves, to staminate plants and to pistillate plants in 

 blossom. Other genera are treated as fully. 



Scientific names used follow the International Code of Botanical 

 Nomenclature. If the name used differs from that used in Gray's 

 Manual or in Britton and Brown's Flora the name used in these 

 works appears as a synonym, followed by G. or B. 



If any adverse criticism were to be made of this book it would 

 probably be of some of the species included or still more probably 

 of species omitted. For example many botanists would not con- 

 sider some of the willows as aquatics and the same would apply to 

 many of the grasses and some at least of the twelve species of 

 Bidens and nine of Aster. On the other hand the river birch 

 {Betula nigra) would seem to deserve a place and certainly as long 

 as any ferns are given the Virginia chain, marsh, and sensitive 

 should be included. But Dr. Fassett anticipated this criticism : "The 

 author is certain that no two individuals would make the same list 

 of species ; it is probable that the same individual would not make 

 identical lists at different times." Because of this uncertainty as to 

 the right of some plants to be considered aquatics the author has 

 evidently included many that he considered doubtful. 



The keys have been tested out for several years in Dr. Fassett's 

 classes and proved easy to use. The book will be helpful to every- 

 one who collects plants in ponds, lakes or marshes and along 

 streams. The illustrations are attractive and add immeasurably to 

 the usefulness of the book. 



The Structure of Economic Plants* 



R. C. Benedict 



Although somewhat belated, it is worthwhile to publish a review 

 of Hayward's "The Structure of Economic Plants." The text is 



* The Structure of Economic Plants. H. E. Hayward. The Alacmillan 

 Co. 1938. 674 pages, 340 figures. $4.90. 



