The first volume was issued several years ago. The other volumes are approaching completion. The work of some of the coadjutors have been issued in advance sheets; at least we have before us the Oaks and Pines by Dr. Engelmann. From this it appears that up to the present time, fourteen distinct species of Oaks have been discovered in California. These are Quercus lobata, Gar-ryana, Douglasii, Breweri, undulata, (also in Rocky Mountains) dumosa, oblongifolia, chry-solepis, tomentilla, Palmeri, agrifolia, Wisli-zeni, Kelloggii, and densiflora. These Oaks pai--take rather of the Mexican than the Atlantic characteristics of the family, and few probably will prove hardy on the Eastern part of the continent. Of Abies (which in our gardens we have hitherto known as Picea) there are five in California, - bracteata, grandis, concolor, nobilis and magnifica. Our old friend, Abies Douglasii, is, however, now to be neither Abies nor Picea, but " Pseudo-tsuga Douglasii." It is the only Californian representative of the genus. The true Hemlocks are Tsuga, of which Mertensiana and Pattoniana make up all.

Of Piceas, (our old Abies) there is now but one, that which we once knew as Abies Menziesii, this is now Picea Sitckensis. Dr. Engelmann finds this to be an earlier name than Menziesii, and though this change will entail much trouble on nurserymen, it is a change which ought to be made, for it is to the advantage of all of us that the rule of priority should be inflexible. It is only because of the respect paid to it that we can get along at all. Of the true Pines, Pinus, Dr. Engelmann finds fourteen in California. 1, Monti-cola; 2, Lambertiana; 3, flexilis; 4, mono-phylla; 5, Parryana; 6, Balfouriana (of which he now makes aristata a variety); 7, Torreyana; 8, ponderosa; 9, contorta; 10, Sabiniana; 11, Coulteri; 12, insignis; 13, tuberculata; 14, mu-ricata. Of these, 14, 13, 12, are not hardy in Philadelphia; 11, 10 hardy only when well screened from wind, - the others do tolerably, but suffer from fungi.