Books and Current Literature 277 



BOOKS AND CURRENT LITERATURE. 



Phytogeography of North America. -Harshberger's monu- 

 mental work, "A Phytogeographic Survey of North America," 

 has recently appeared as the thirteenth volume of Engler and 

 Drude's series ' ' Die Vegetation der Erdc. ' ' * 



The volume comprises (a) a sketch of the history of botan- 

 ical exploration and botanical institutions in America (45 pp.), 

 (b) a description of the salient features of the geography and 

 climatology of North America, with some statistics of the flora 

 (77 pp.), (c) a literature list (47 pp.), (d) an outline of the geo- 

 logical history of the flora (77 pp), (e) a description of the ' 'phy- 

 togeographic regions, formations and associations" of North 

 America (359 pp.). The first two of these sections are inserted 

 in accordance with the custom of some of the volumes of Die 

 Vegetation, the first being quite as detailed as is necessary to 

 the purpose of the volume, the second very cursory and well 

 designed to orient the foreign reader of the following pages. The 

 bibliography, for which the author does not claim completeness, 

 is a very full one and forms an extremely useful feature of the 

 book. The outline of the geological history of the flora takes 

 up the thread at the commencement of the Cretaceous, the mo- 

 ment from which the history begins to throw strong light on the 

 present assorting of the flora. The influences ot the changes 

 in the configuration of the continent during Cretaceous and 

 Tertiary time and of the occurrence of the glacial period are 

 treated in detail for the several phytogeographical regions. 

 This section of the volume is well done, and to it belongs a large 

 share of the interest of the book. We have had no comprehen- 

 sive treatment of the phytogeography of North America, as 

 interpreted by the geological history of the flora, for 30 years, 

 a period during which geology and paleobotany have made 

 great strides. The description of the vegetation of the contin- 



*Harshberger, J. W. Phytogeographic Survey of Xorth America. Die Vegetation der 

 Erde Vol. 13. pp. 863, 32 figs., 18 pis., 1 map Leipzig, Engelmann. 1911 (S13.00). 



