quarter of the world, yet it is scarcely probable that Columbia will supersede America. In our science the names established throughout the works of Linnæus are become current coin, nor can they be altered without great inconvenience. Perhaps, if he had foreseen the future authority and popularity of his writings, he might himself have improved upon many which he adopted out of deference to his predecessors, and it is in some cases to be regretted that he has not sufficiently done so. In like manner, the few great leaders in natural knowledge must and will be allowed to ward off and to correct, from time to time, all that may deform or enfeeble the prevailing system. They must choose between names nearly of the same date, and even between good and bad ones of any date. A botanist who, by the strength of his own superior knowledge and authority, reforms and elucidates a whole tribe of plants hitherto in confusion, as a Hedwig in Mosses, or Acharius in Lichens, ought to be unshackled in every point in which he can be of service. His wisdom will be evinced by extreme caution and reserve in using his liberty with re-
