16 Part I. Chapter 1. 
' The later books on the flora of Pennsylvania may be said to begin 
with a Botany of Pennsylvania by CHas. B. TREGO, which appeared in a Geo- 
graphy of Pennsylvania in 1843. HENRY R. NoLr’s Flora of Pennsylvania and 
Botanist’s Pocket Manual ı851. Journal of a Botanical Excursion in the North- 
eastern Parts of the States of Pennsylvania and New York during the year 
ı807 by FREDERICK PURSH was printed for the first time in 1869 and edited 
by Thomas P. James. In 1862 GEORGE SMITH published in the History of 
Delaware County, Penna. a description of the botany of the County. AUBREY 
H. SMITH issued a paper in 1867 on Colonies of Plants Observed near Phila- 
delphia. THoMAs C. PORTER’s Enumeration of the Indigenous Plants of Lan- 
caster County, Pennsylvania was incorporated in MOMBERT’s Authentic History 
(Lancaster 1869). A sketch of the botany of the state by the same botanist 
was published in WALLING and GRAY’s New Topographical Atlas of the State 
of Pennsylvania (1872). A Catalogue of the Flowering Plants and Vascular 
Cryptogams found in and near Lackawanna and Wyoming Valleys by WILLIAM 
R. DuUpLEy and CHARLES O. THURSTON appeared in 1892. THos. C. PORTER 
published in 1898 in the Bulletin of the Torrey Botanical Club a description 
of the Flora of the Lower Susquehanna and issued privately in 1900 a small 
pamphlet entitled Rare Plants of Southeastern Pennsylvania. The ecologic 
aspect of the Pennsylvania flora has been presented in a paper by ALEXANDER 
Mac ELWEE, The Flora of the Edgehill Ridge near Willow Grave printed 
in the Proceedings of the Academy of Natural Sciences of Philadelphia and 
Flora of the Serpentine Barrens of Southeastern Pennsylvania by J. W. HARSH- 
BERGER published in Science, and a Phytogeographic Sketch of extreme South- 
eastern Pennsylvania in the Bulletin of the Torrey Botanical Club for March 1904 
by the same author. Finally in 1903 appeared Flora of Pennsylvania by THOMAS 
C. PORTER edited with the addition of Analytical Keys by Joun K. SMALL. 
This work of three hundred and sixty two. pages is a carefully annotated 
list of the plants of the state with notes on their geographic distribution by 
counties. 
The flora of the State of Delaware is meagerly represented by published 
accounts. In 1860 EDWARD TATNALL published a Catalogue of the plants 
of New Castle County, and in 1902 in the Botanical Gazette, LETITIA M. SNOW, 
a paper entitled Some Notes on the Ecology of the Delaware Coast. The 
flora of this state has however, received attention from WirLıam M. CANBY, 
a resident of Wilmington, who amassed a fine herbarium of the plants of his 
native: state, as also various other parts of the United States and foreign 
countries. This herbarium was purchased by the College of Pharmacy of 
the City of New York and deposited in their building. J. T. PENNYPACKER 
has also actively collected plants in the State, — 
The Southern United States have been carefully worked over by botan- 
ists usually non resident in that section, so that the stimulus which comes 
from the presence of coteries of botanists in the different cities and towns in 
the institutions. of. learning, which are nöt numerous and have been backward 
