197 



continent, and that Artemesia tridentata is of the "senecoid com- 

 posites" (p. i88), instead of being in the tribe Anthemideae, do 

 not necessarily detract from the usefulness of the work, for these 

 are questions of taxonomy, and not details that one must expect 

 every phytogeographer to record with unerring accuracy. 



After describing, in chapter four (pp. 311-341), the afifinities 

 of the North American flora, comparing each of the sections with 

 neighboring regions,* or those further removed that have con- 

 tributed floral elements, the author takes up, in the fifth chapter, 

 the classification of North American phytogeographic regions. 

 Citing among others, those previously published by Grisebach, 

 Engler, Drude, Merriam (whose classification, by the way, was 

 as much zoological as botanical), and Clements, with the state- 

 ment that Engler's classification of 1902, seems to the author 

 "the most complete and satisfactory," Dr. Harshberger writes 

 thus: "The classification presented herewith (his own) repre- 

 sents, the writer believes, the present status of our knowledge 

 concerning the geographic distribution of American plants. In 

 it is incorporated all that is good in the classifications that have 

 preceded, without sacrificing originality." 



IV. North American Phytogeographic Regions, Forma- 

 tions, Associations. The fourth and much the longest part 

 of this work is taken up with a particular description of the 

 vegetation as it is to-day and as it impresses the author. There 

 are many who will cherish the thought that this enormous amount 

 of labor (pp. 347-704) might well have been left to form the 

 nucleus of another book. And this, not only because the minute 

 description of plant formations and associations is as much eco- 

 logical as phytogeographic, but also because of the vast amount of 

 more or less stereotypic repetition that must ensue in the descrip- 

 tion of closely related areas which differ only in minor details; a 

 repetition almost wearisome, in a book of this character, but 

 interesting enough in a sketch of more or less limited areas, or a 

 small • series of them. The account of the vegetation of the 

 Arctic tundra and of the peculiar formations of Alaska, Labrador, 



*The citing of Phyllospadix of the Zosteraceae, on page 313, as an example of 

 endemism, under arctic algae, is an unhappy slip of the pen. 



