INTRODUCTION. 



That the Seooml Part mav be understood bv ihc bcjrinner. and the 

 method ol" using it made easy to him, we shall dovoto tlic Introduc tion to 

 the Analysis of a few common plants, on which the student may 

 practice, and by lbllowin«» a similar course with other plants, he may deter- 

 mine, in most cases, with little difficulty, their orders, genera and species. 

 All plants are arranged in two great divisions; F'lotcerinir and fVaiccrUss 

 plants; that is, such plants as produce flowers, constituting the first di\is- 

 ion, and such as produce no flowers, the second. Of the fonner, are all 

 the most common and abundant vegetables; of the latter, Ferns, Mosses. 

 Lichens, &c. These dilTerent divisions of vegetables, which are distinctly 

 separated from each other by nature, have received dilTerent names from 

 diflercnt Botanists. accorcUng to the point of distinction on which they 

 founded their classification. The plants of the first division were called 

 Phoiogainou.t, by Linnaeus, from having the organs of fructification visi- 

 ble. Those of the second, Crt/ptogamous, for the reason that the same 

 organs were wanting, or inconspicuous. Jussieu called the plants belong- 

 ing to the first division Cotyledonoits, from the seeii having cotyleilons, and 

 those of the second ArotijkJonous, from the absence of these organs. Rich- 

 ard calls the first division Einbryoyiatcc, from the circumstance that th(^ 

 seeds of these plants always contain a rudimentary' root and stem, and the 

 second ExembryonattE. from the absence of an embr)"o. 



De Candolle applies the terms Vasculares and Cdhdares to the two great 

 di>'isions, meaninfj by the former term, that the plants of the first ihvision, 

 to wliich it is applied, contain a vascular system, with spiral vessels forming 

 a |>art of it : and by the latter term, that the plants of the second di\'ision. 

 to which it is applied, have no such system, containing spiral vessels. Ras- 

 jiail makes quite a dilTerent di\'ision of plants; but, so flir as we know, no 

 Botanist has adoptoil his plan. He divides all plants into Socturnal. or 

 such as grow at night, or ui the dark, and Diurnal or such as grow in the 

 day 



Flowerinfi jjlants are divided (as the student will see, by turning to the 

 first page o{ the Analysis, at the beginning of the Second Part.) into twu 

 classes, the di.stinction depending on the manner of growth. 



Ci..\ss I. Exogens. A name given to this class from the fact that the stems 

 of the plants of this division increa.se by external layers of new wockI, a-s 

 in our forest trees. The plants of this class may W readily known, by 

 having a conical trunk, composed of harh\ xrood and pith ; the wootl arrangcul • 

 in concentric layers;, leaves articulated with the stem, with the veins 

 branching an<l reticulated. Examples. Trees, Shrubs, Beans, Potatoen 

 Pinks Hoso« i.^c. 



