Very few persons who love flowers have any adequate idea of how much they owe to the working botanist, whose labors systematize knowledge, so that any one can readily find out all that is known of what has gone before. Horticulturists have continually to look to the Botanists for advice and assistance. Without the Botanists our art and pursuits would be shorn of half their charms. This work of Mr. Watson's is just one of those pieces of hard labor that is extremely valuable to everybody, and yet without any chance of that glory which springs from what are known as original investigations or brilliant speculations. It is simply a work of reference. It gives the book, with page and in order of publication, so that any one can turn to the original authors for what he wants to know. For instance, about the yellow Locust, or Robinia, the first author is Linnaeus Gen. PI. 1, p. 101. Then Du Roi"Obs." Bot. 28. The next authority is our own, Walter"186," and then follow some twenty-five others, including Loudon, Curtis, Torrey, Gray, Chapman, and other familiar names. The monopetalous plants will follow as soon as Mr. Watson gets it ready.

Mr. Watson, on application to his address, Cambridge, Mass., will furnish it for $2 and postage, which as it contains 475 pages, one can imagine to be not one-half its cost. We hope, however, Mr.Watson will receive large orders for it, for he aeserves all the encouragement we can give him to keep on with this very hard but very useful work. As a full catalogue of the plants of the United States, it has great value; as heretofore few knew where to look for them, scattered through scores of books and serials.