Page:An introduction to physiological and systematical botany (1st edition).djvu/434

 404 out the Class of a plant, before we can settle its Order.

The Linnæan System, however, like all human inventions, has its imperfections and difficulties. If we meet in gardens with double or monstrous flowers, whose essential organs of fructification are deformed, multiplied, or changed to petals; or if we find a solitary barren or fertile blossom only; we must be at a loss, and in such cases could only guess at a new plant from its natural resemblance to some known one. But the principal imperfection of the System in question consists, not merely in what arises from variations in number or structure among the parts of a flower, against which no system could provide, but in the differences which sometimes occur between the number of Stamens, Styles, &c., in different plants of the same natural genus. Thus, some species of Cerastium have only 4, others 5, Stamens, though the greater part have 10. Lychnis dioica has the Stamens on one plant, the Pistils on another, though the rest of the genus has them united in the same flower; and there are several similar instances; for number in the parts of