PART 11. 
CLASSIFICATION OF PLANTS. 
Every plant which grows on the surface of the earth or in the 
waters constitutes a distinct individuality. The careful examina- 
tion and comparison of a certain number of these individuals 
of the Vegetable World will lead to the admission that many are 
quite identical in some of their characteristics, while others 
possess no character in common. Examine the individual plants, 
for instance, which compose a field of oats; in each the root, the 
stem, the flowers, the fruit, present the same identical characters. 
The seed of any one whatever of these plants will yield other 
plants like those of the field. Every individual in the field belongs 
_ to the same species—to the species Avena 
The species, then, is a collection of all the individuals which 
resemble each other, ie which will reproduce other individuals 
like themselves. 
These species may present, as the result of diverse influences, 
such as change of climate or cultivation, differences more or less 
marked—tendencies more or less tenacious in resisting efforts to 
withdraw them from the original type. To these, according to theit 
importance, botanists give the name of varieties and sub-varieties. 
‘The Wheat-plant, the Vine, the Pear, the Apple, and most of our 
cultivated legumes, all yield, under the influence of culture extend- 
ing over along series of years, plants altogether different from the 
original in their exterior; but they preserve, one and all, the 
essential characters of the species. They are varieties of the 
Wheat-plant, of the Vine, of the Pear, of the Apple. 
The assemblage of a certain number of distinct species present- 
3 o 
