41 



makes it a very serviceable book. It contains very clear and con- 

 cise descriptions of 649 genera, 2,733 species, and 186 varieties. 

 Synonyms, numbering 1,788, are inserted with the species 

 descriptions thus increasing the value of the book. The keys to 

 genera and species appear to be accurate and clear so far as they 

 have been tested by the writer. 



In priority of names and in segregation, exception is frequently 

 taken to Dr. Rydberg's publications. There is a return to such 

 long used and satisfactory family names as Leguminosae, Gram- 

 ineae, Cyperaceae, Umbellifefae, Cruciferae, and Compositae. 

 Pinus, Apimis, and Caryopitys are included in the single genus 

 Pimis. The number of species of Quercus has been some- 

 what reduced. In this genus distinctions have at times been 

 made of which the characters ascribed to separate species may 

 sometimes be found to occur on a single tree or shrub. This 

 reduction should meet with general approval, as will the contrac- 

 tion of Giitierrerda into five seemingly well-defined species. 

 Among the Gramineae Miihlenbergia contains seven species and 

 one variety, and Poa is reduced to twenty-five species. Astra- 

 galus has again come to its own, the seventeen genera of Dr. 

 Rydberg are brought together into this single genus. And yet 

 the reduction in the number of species within genera is not the 

 policy throughout the manual. When species and varieties are 

 clearly defined they are given a space. Thus there are described 

 twenty-four species of Mertensia and fifty-four species and varie- 

 ties of Pentsteuion. Many other examples might be enumerated. 



The best test of the general value of such a manual will be its 

 usefulness to others than the trained systematist. The authors 

 are to be congratulated on having given us a book with work- 

 able keys, clear descriptions, and at the same time to have in- 

 cluded practically all well-defined species. 



Edward C. Schneider 

 Colorado College, 



Colorado Springs, Colorado 



