that the extremely scarce plants of the Welch and Scotch Alps, reward the toil of the Botanist.
To those long conversant with this science, the natural arrangement, generally adopted by the French school, would seem to have given the preceding pages the air of greater research; but the Linnaean method, though artificial, has been chosen: for, as Dr. Hooker justly remarks, "the experience of a hundred years has proved to every unprejudiced mind, that no system can be compared to that of the immortal Swede, for the facility with which it enables any one hitherto unpractised in botany to arrive at a knowledge of the genus and species of a plant." And as the chief value of these memoranda will be in assisting those who are commencing their botanic career, an enumeration of genera and species
adapted to their line of study was to be preferred.
One of the first difficulties the student will have to encounter is the unsettled state in which he will find many genera, and far more species, of plants, so common as to be met with in every hedge and wood; for, unfortunately, scarcely two botanists of the present day can agree upon what should constitute generic, much less specific, distinctions. This may appear a startling assertion, but in making it I am borne out by one of the best and most accomplished botanist of our time, whose ideas on this subject I shall take the liberty to give in his own words. " In nothing is more consideration now required than to determine what of new genera ought to be adopted and what rejected. Had you and I begun our botanic career when old Dickson was in his prime, we should have had the same aversion to the Hedwigian improvements which he had, but which have nevertheless tended so very much to the advancement of muscology. At the same time I must agree with you, that modern Botanists are carrying their ideas of division and subdivision to a most unwarrantable length, and that they are thereby doing an injury rather than a benefit to science, and are deterring many from undertaking the study altogether. I must not be supposed to condemn the subdivision of genera on every occasion. If there is a distinction in the habit of the plant, and a different mode of fructification at the same time, then I will allow the genus may be a good one. Then again there
