By William Trelease, Ithaca, N. Y. Published by the U. S. Department of Agriculture. If this work had no other merit, the long list of references to works treating of the subject would make it of inestimable value. In regard to the classification of plants, it is demanded of an author that he already knows what his predecessors have done; but in other departments of plant knowledge this has not been insisted on, and thus we often find the most distinguished botanists wasting time and money in publishing what has been long known before. Such labors as this of Mr. Trelease do much to remedy this evil. It is not as complete as it might be. For instance, we note Prof. Asa Gray credited with a paper on "Dimorphism in Forsythia" in 1873, but another author had a paper on this subject a couple of years or so before in the Proceedings of the Academy of Natural Sciences of Philadelphia, but which is not credited to that author in the bibliography before us. We merely mention this as a suggestion that those who may be disposed to investigate the subject may not merely start where Mr. Trelease left off, but go over again, once in a while, the whole subject from the beginning.

As to the matter of the work itself, it may be sufficient to say, that Mr. Trelease belongs to that class of naturalists who believe that every process which is carried on in a plant is for the plant's individual benefit, and by the operation of this effort "natural selection" is brought about. It is well known that there are innumerable processes going on in individual plants that are of no benefit to it whatever; but naturalists of this group make short work of these facts, by assuming, in the language of our present author, that a power "once developed and endowed may continue for generations after their necessity has ceased to exist." In this, as in so many other assumptions, there is partial truth, but it by no means covers all the ground.