90 tfATtJJ&AL ORDERS. 



species of Amygdalus ; Pear, Apple and Quince, three 

 species of Pyrus ; Currant and Gooseberry, two spe 

 cies of Ribes. These all belong to the same Natural 

 Order, POMACEJE of Linnaeus. 



Observation The relation between these several genera is 

 obvious even to a common observer, by their habit* or general 

 aspect. 



These relations may he represented in the following 

 manner : 



NATURAL ORDER. GENEHA. SPECIES. 



~Prunus. {Cherry, 

 | Plum. 



POMACEJS.- 



Jhnygdab*. | Bering Almond, 



f Pear, 



Pyms. -j Apple, 



I Quince. 



Ribes -f Currant ' 



| Gooseberry. 



There is a tendency in the vegetable kingdom to- 

 wards the following general relations, upon which 

 Natural Divisions, such as Natural Orders, Genera, 

 &c. are (bunded. 



1. All the individuals which compose 1 it are united 

 by affinities into one common bond, in which there is a 

 gradual transition from one point to another, the vari- 

 ous individuals standing as so many points of an ex- 

 tended series, or so many links of a continued chain. 

 Thus one plant has a certain set of characters ; anoth- 

 er loses some of these and acquires some new ones; 

 another loses some more, and acquires other new ones, 

 <S;c, until the two extremes are quite different from each 

 other. 



2. In this general series Natural Orders are related 

 to each other. The various Gercra of the same natural 

 order are related on one extreme with one natural or- 

 der, and, passing through a gradual series, approach 



* By habit in botany is meant the general port or appearance of a plant, which 

 strikes the observer at once, and cannot be very well denned. 



