No. 523] NOTES AND LITERATURE 



445 



Floristic investigations have been undertaken by Professor 

 J. J. Thornbur, botanist of the Arizona Experiment Station, and 

 reported in an effective manner under tlie title Vegetation Groups 

 of the Desert Laboratory Domain (Chap. IV, pp. 103-112). In 

 this contribution, floristic studies, instead of being dry lists of 

 species, are made to contribute materially to the chief ques- 

 tions as to the origin, association and movements of the vegeta- 



In the chapter devoted to defining plant associations and habi- 

 tats, pages 24 to 27 embrace an account of the lichens of the 

 Laboratory domain, by Professor Bruce Fink, of Miami Univer- 

 sity. 



Distributional maps with accompanying notes were prepared 

 by Mr. J. C. Blumer, of the laboratory staff. In the reviewer's 

 opinion maps of this sort, showing, as they do. location and indi- 

 vidual frequence of notable species, are of essential help to the 

 reader, as thev must have been indispensable to the writer of the 

 book. 



Finally, among the collaborative contributions is a chapter 

 (V, pp. 113-119) on the Origin of Desert Floras, by Dr. D. T. 

 MaeDougal. director of the Desert Laboratory and of the Di- 

 vision of Botanical Research of the Carnegie Institution of 

 Washington. 



In this study of the vegetation of the Desert Laboratory domain 

 Professor Spalding has led the attack from the plant side, seek- 

 ing to define the actual conditions of distribution, association 

 and movements in the vegetation as a whole and specifically in 

 the case of prominent desert species, and always with a view to 

 relating facts of distribution, structure, etc., with the environ- 

 mental conditions under which they have been worked out. 



Accordingly, a considerable portion of the book is of a descrip- 

 tive nature. Chapter I presents the plant associations and habi- 

 tats of the laboratory domain. The author distinguishes some 

 twelve associations exclusive of parasitic and symbiotic plants 

 and miscellaneous introduced species, meaning by "association*" 

 an aspect or phase of vegetation, such, for example, as the 



chaparral made up chiefly of palo verde and catclaw or, on the 

 other hand, of Mexican -.Tease wood. These associations reflect 

 topographic and soil conditions of the area. Remembering the 

 traditional view as to the hostility of the desert toward plants, 

 one is rather surprised to learn that this inhospitable domain 



