By Asa Gray. Professor Asa Gray, though he must have no very distant views of a " threescore and ten," still continues to work as hard as ever, for which the great world he lives but to benefit by his knowledge, will be very grateful. This essay, contribued to the American Academy of Arts and Sciences, is one of great value. It is entitled studies of Aster and Solidago in the older Herbaria. The "year in Europe" which so many take for relaxation, was chiefly spent by Dr Gray in examining material for the continuation of his synopsis of the Flora of North America. In the course of his studies he found very much which threw light on these two very difficult North American Genera, and this information is the chief topic in this " contribution." Then there are descriptions of new plants of Arizona and adjacent districts, of interest to horticulturists; may be a new horse-chestnut, AEsculus Parryi, allied to A. Californicus; a new blackberry, between Rubus pedatus and R. chamae-morus, called R. lasiococcus, although these species have not, so far, entered in any way into garden culture; a new Ribes of the black currant section, R. viburnifolia; several new Pent-stemons and a large number of composite plants. There are eighty-eight new species in all.

When we remember that it takes an immense amount of research before we can be sure an unknown plant is new, we may have some idea of the great labors of Dr. Gray on this large number.

The number also shows that this great country has by no means been all explored when such a great number of novelties can be found in two or three years of botanical rambles. Many engaged in this work have not been forgotten by Dr. Gray, and we find among the new plant names, some in honor of such well known collectors; as Pringle, Gattinger of Nashville, Rothrock, Lemmon, Vasey, Mohr of Mobile, Wright, Muir, Palmer, Shockley, Lemmon, Parry and the Parishes. Dr. G. pays a well-deserved compliment to these energetic brothers, and gives an entirely new genus to Mrs. Lemmon, under the name of Plummera floribunda, "under the name which she until recently bore, the partner of her husband in the severe labors and privations of Arizona exploration, and in the honor of this and of many other interesting discoveries." It is a composite, and the affinity may be with actinella.