SPECIES AND GENERA. 111 
CHAPTER XV. 
SYSTEMATIC BOTANY. 
§1. OF THE CLASSIFICATION OF PLANTS. 
330. Systematic Botany relates to the arrangement of plants 
into groups and families, according to their characters, for the 
purpose of facilitating the study of their names, affinities, habits, 
history, properties, and uses. 
331. The student in botanical science is introduced into a boundless field of 
inquiry. The subjects of his research meet him at every step: they clothe the 
hill and the plain, the mountain and the valley. They spring up in the hedges 
and by the wayside; they border the streams and lakes, and sprinkle over its sur- 
face; they stand assembled in vast forests, and cover with verdure even the 
depths of the ocean; they are innumerable in multitude, infinite in variety. Yet 
the botanist proposes to acquaint himself with each individual of this vast king- 
dom, so that he shall be able readily to recognize its name, and all that is either 
interesting, instructive, or useful concerning it, whenever and wherever it is pre- 
sented to his view. . 
332. Now it is obvious, that if the student should attempt the accomplishment 
of this task by studying each individual plant in detail, whether with or without 
the aid of books, the longest life would scarcely be sufficient to make a begin- 
ning. 
333. But such an attempt would be as unnecessary as fruitless. The Author 
of Nature has grouped these myriads of individuals into spEcrEes (50). When 
he called them into existencé in their specific forms, he endowed each with the 
power of perpetuating its own kind and no other, so that they have descended to us 
distinguished by the same differences of character and properties as at the begin- 
ning. When, therefore, the student has become acquainted with any one indi- 
vidual plant, he is also equally acquainted with all others belonging to the same 
species. 
a. Thus a single stalk of white clover becomes a representative of all the mil- 
lions of its kind that grow on our hills and plains, and a single description of the 
white pine will answer, in all essential points, for every individual tree of that 
ancient and noble species, in all lands where it is found. 
334. Again, the species themselves, although separated from each other by 
obvious differences, still are found to exhibit many constant affinities, whereby 
they are formed into larger groups, called GENERA (52). Thus the white clover 
and the red (Trifolium repens and T. pratense) are universally recognized as of 
different species, but of the same genus; and a single generic description of any 
10* 
~ 
