Specialities on the plant-forms already enumerated. Physiognomy of plants discussed from three different points of view: the absolute difference of the forms, their local preponderance in the sum total of the phanerogamic Floras, and their geographical as well as climatic dispersion—pp. 296–346. Greatest height of arboral plants; examples of 223 to 246 feet in Pinus Lambertiana and P. Douglasii, of 266 in P. Strobus, of 300 feet in Sequoia gigantea and Pinus trigona. All these examples are from the north-western part of the New Continent. The Araucaria excelsa of Norfolk Island, accurately measured, rises only from 182 to 223 feet; the Alpine palms of the Cordilleras (Ceroxylon andicola), only 190 feet—pp. 322–324. A contrast to these gigantic vegetable forms, presented not merely by the stem of the arctic willow (Salix arctica, two inches in height,) stunted by cold and exposure on the mountains, but also in the tropical plains by the Tristicha hypnoides, a phanerogamic plant which is hardly three French lines (quarter of an inch) in height, when fully developed—pp. 324–325. Bursting forth of blossoms from the rough bark of the Crescentia Cujete, of the Gustavia augusta, from the roots of the Cacao tree. The largest blossoms borne by the Rafflesia Arnoldi, Aristolochia cordata, Magnolia, Helianthus annuus—p. 348. The different forms of plants determine the scenic character of vegetation in the different zones. Physiognomic classification, or distribution of the groups according to external facies, is from its basis of arrangement entirely different from the classification according to the system of natural families. The physiognomy of plants is based principally on the so-called organs of vegetation, on which the preservation of the individual depends; systematic botany bases the classification of the natural families on the consideration of the organs of reproduction, on which the preservation of the species depends—pp. 348–352. ON THE STRUCTURE AND MODE OF ACTION OF VOLCANOS IN DIFFERENT PARTS OF THE EARTH— pp. 353–375.