Page:An introduction to physiological and systematical botany (1st edition).djvu/394

 364 seem to me very capable of being well discriminated by their seeds, and other botanists have held the same opinion.

But though I feel convinced, as far as my experience goes, that genera are really founded in nature, I am far from asserting that Linnæus, or any other writer, has succeeded in fixing all their just limits. This deep and important branch of natural science requires the union of various talents. Many persons who can perceive a genus cannot define it; nor do acuteness of perception, solidity of judgment, and perspicuity of expression, always meet in the same person. Those who excel in this department are named by Linnæus, ''Phil. Bot. sect.'' 152, theoretical botanists; those who study only species and varieties, practical ones.

In methodical arrangement, whether natural or artificial, every thing must give way to generic distinctions. A natural system which should separate the species of a good genus, would by that very test alone, prove entirely worthless; and if such a defect be sometimes unavoidable in an artificial one, contrivances must be adopted to remedy it,