40 Part I. Chapter ı. 
GRISEBACH’s Die Vegetation der Erde in two volumes 1884 contains much 
of interest. Atlas der Pflanzenverbreitung by DRUDE contains a map of North 
American plant regions. DrUDE’s Handbuch der Pflanzengeographie 1890 
should also be consulted, as also ENGLER’s Versuch einer Entwicklungsgeschichte 
der Pflanzenwelt (1879). MERRIAM’s Geographic Distribution of Life in North 
America printed in Annual Report Smithsonian Institution (1891) is historically 
important. The Metaspermae of the Minnesota Valley by ConwAY MACMILLAN 
1892 is invaluable. CovILLe’s Botany of the Death Valley Expedition 1893 
is an important work for the desert region. Pflanzengeographie auf physio- 
logischer Grundlage by the late Dr. A. F. W. SCHIMPER 1898 is a fine re- 
ference book for many interesting details. Life Zone and crop Zones by 
_ MERRIAM 1898 was issued as a bulletin of the United States Biological Survey. 
KEARNEY’s Report on a Botanical Survey of the Dismal Swamp Region 1901 
is important. The Phytogeography of Nebraska by Pounp and CLEMENTS 
1900, Plant Life of Alabama by CHARLES MOHR 1901 and Flora of Washington 
by C. V. PipPER 1906 about complete the list of the most important works on 
the phytogeography of North America. 
2. Physiography and Soils. 
The number of separate monographs papers and books on the physio- 
graphy, soils and geology of North America is too vast to present even in 
an abbreviated form in this section. Only those publications will be mentioned 
which seem to be especially useful for consultation in connection with phyto- 
geographic work. The study of North American physiography (physical geo- 
graphy) and geology has gone hand in hand, but a detailed and scientific study 
of the superficial soil formation is of comparatively recent date. The Geological 
Survey of the United States publishes both bulletins, monographs and annual 
reports and a series of topographic and geologic maps which are intended to 
cover finally the entire territory of the United States. These have been fre- 
quently consulted in the preparation of this volume. The variety of topics 
which must be considered by the plant geographer is indicated in the following 
titles. The causes which have led to the production of Cape Hatteras by 
N. 5. SHALER in the Proceedings of the Boston Society of Natural History for 
1872 is a. sample. Lakes and Valleys in Northeastern Pennsylvania is the title 
of an artice by Wm. M. Davis, in first volume of the National Geographic 
Magazine. ROBERT T. HıLL contributed to the American Geologist in 1890 
(9, 65) a paper entitled Classification and Origin of the Chief Geographic 
Features of the Texas Region and an article on The Making of Pennsylvania 
is suggestive. 
The first report of the United States Board on Geographic Names was 
printed by the government in 1891. E. W. HILGARD furnishes an account 
of the physical and industrial geography of California to the Geographical 
Journal of 1893. The National. Geographic Magazine for 1894—95 contains 
a valuable contribution on the Geomorphology of the Southern Appalachians 
