IN taking "toadstools" as the text of a little botanical discourse, we start with a familiar notion if not a scientific one; but all science begins with common ideas which it corrects, extends, and develops. Everybody knows what toadstools are, odd-looking things that grow up in the fields and are often kicked aside in rural rambles, of no use to man or beast, and "pizen" to eat. This is the oldest, the widest, and the lowest state of mind upon the subject. But many have got beyond this, and recognize that some of these queer-looking things are actually eatable; these they distinguish as mushrooms, and all the rest are lumped together as toadstools. A step forward, and we become slightly scientific; that is, the different kinds begin to be noted, and compared, and classed with reference to their particular characters. When so much is gained, it soon appears that the subject is much wider than was supposed, and that all these growths are but parts of an extensive division of peculiar plants called fungi; and, having reached this state of intelligence, toadstools have disappeared. While, then, the popular term may answer to indicate generally what we are talking about, it conveys no exact meaning. The group of plants represented upon the plate is not merely a family of toadstools, but a collection of fungi. By their unlike characters they belong to separate groups in this class, and each has its separate name; for* nomenclature must keep pace with science, and its higher discriminations require separate technical terms to mark them. Some people cry out against a few strange words in botany, and make it an excuse for neglecting the study; but the real reason is, a lack of interest in the knowledge of Nature, for they are generally ready enough to spend whole years in the acquisition of strange words by the thousand in. foreign languages, living and dead. Scientific terms have an educational value, because they involve and give precision to new ideas, while in acquiring an additional language we are only obtaining new terms for old ideas.
