vi INTRODUCTION. 
seem to some to be too radical, no doubt is entertained that time will fully justify these 
changes in the judgment of all, and demonstrate that the permanent advantages to Botanical 
Science will far outweigh any temporary inconveniences, as has been already so fully shown 
in Ornithology and other zoGlogical sciences. 
The work will be completed in three volumes and will be issued as rapidly as it can be 
printed, the text being already written and the figures drawn. 
Area. 
The area of the work extends from the Atlantic Ocean westward to the 102d Meridian, a 
little beyond that of Gray’s Manual, so as to include the whole of the State of Kansas; and 
northward from the parallel of the southern boundary of Virginia and Kentucky to the north- 
ern limits of Labrador and Manitoba. For convenience, the whole of Nebraska has been in- 
cluded, thus permitting the illustration of practically the entire Flora of the northern por- 
tion of the Great Plains. 
The Flora of Canada and the British possessions not being distinguishable by any well 
marked features from that of the adjacent parts of the United States, and not embracing 
more than about 300 additional species, it was deemed best to include this more northern ter- 
ritory, in order to present a manual of the whole Flora of the northeastern part of the con- 
tinent, with the exception of that of Greenland and the Arctic Circle, which is much the 
same on both continents; nearly all the Arctic plants are, however, included, as but very few 
of them are strictly confined to the Arctic Zone. 
Figures. 
Within the above area there are over 4,000 recognized species, more than three times the 
number in Bentham’s Illustrated Handbook of the British Flora. To illustrate all these ina 
work of moderate size and cost, only parts of each plant could usually be figured, and these 
mostly below life-size. To exhibit full-page illustrations would have added fourfold to the 
bulk of the work, and the consequent more limited sales would have necessarily increased 
the price in a much greater proportion, and thus have thwarted the primary object, viz., to 
supply a work adapted to general circulation and use. On the other hand, it was found that 
any considerable further reduction of the figures in order to reduce the size of the work, would 
be at the sacrifice of the clearness and usefulness of the illustrations. 
In the general plan adopted and in giving parts only of the larger plants, it has been the 
constant aim to make the reduction of each figure as little below life-size as possible, to select 
the most characteristic parts for illustration and to preserve the natural proportions. In 
these respects, it is believed, the present work will be found to be at least not inferior to that 
above named and often superior. 
The cuts are all from original drawings for this work, either from life or from herba- 
rium specimens, though reference has constantly been made to published plates and figures. 
All have been first drawn life-size from medium-sized specimens, and afterwards reduced to 
the proportion indicated by the fraction near the bottom of each cut, most of them being 
from % to 24 of medium life-size. By this method the illustrations do not suffer from the 
use of a magnifier, but are improved by it and regain their full expression. 
Enlargements of special parts are added in most of the illustrations in order to show 
more clearly the floral structure, or minute organs, or the smaller flowers. These are in vari- 
ous degrees of enlargement, not deemed necessary to be stated. The figures are uncolored, 
because coloring, except in costly work, obscures the fineness of linear definition and injures 
the cuts for descriptive and educational uses. 
The Classification of Plants. 
The Plant Kingdom is composed of four Subkingdoms, or primary groups: 
1. Thallophyta, the Algae, Fungi and Lichens. 
2. Bryophyta, the Mosses and Moss-allies. 
3. Pteridophyta, the Ferns and Fern-allies. 
4. Spermatophyta, the Seed-bearing plants. 
The subkingdoms are divided into Classes, the Classes into Orders, the Orders into Fam- 
ilies, the Families into Genera, and.the Genera into Species, a species being composed of all 
the individuals of a kind capable of continuous successive propagation among themselves, 
and being the only group marked out by nature by such a definite and positive boundary. 
