Flora of tlhe Hawaiian Islalids.1 Insular floras are always peculiarly interesting, and few are more so than that of the Hawaiian Islands. Lying so far removed from all continents, these islands present important problems to the geographical botanist. During a residence of twenty years Dr. Hillebrand unremittingly studied the Hawaiian flora, thoroughly exploring the whole region and cultivating very many of its native plants. This book, embodying as it does the results of such protracted study,
... h protracted study, is more than a mere manual, for it contains most valuable notes upon the peculiarities of the flora and offers many suggestions as to its origin. It is a pity that the author was not spared to correct the proof-sheets and to develop his notes, which are given as mere memoranda, but the editing has evidently been very conscientiously done by his son, assisted by Professor Askenasy, of Heidelberg. An introduction of twenty pages gives a general account of the position and nature of the Hawaiian Islands, as well as the striking features of its flora. Then follows Mr. Bentham's " Outlines of Botany," from his British and Colonial Floras, with a good glossary. The diversity of conditions, and hence of the flora, of the different islands is so great that in our limited space we can give no account of it, although it is presented in a very clear and interesting way. Five different zones of elevation are described, called the "lowland zone," mostly grass-covered after rains, with isolated clumps of trees; the "lower forest zone," with rather open woods, characterized by the pale green foliage of Aleurites Moluccana; the "middle forest zone," within the region of the clouds, and luxuriant in trees and jungle, and with a great exhibition of Lobeliacee, " the peculiar pride of the flora;" the "upper forest zone," characterized by stunted trees; the ' bog-flora" of the high table-land of certain islands. A comparison with other floras brings out the striking difference in the great number of varieties in all the species of the principal genera, as though nature had run wild in the production of diverse forms. These islands seem to be the only ones of the Polynesian group which contain a large proportion of indigenous plants with American affinities, while Australian types are wanting or very scantily represented. Southern Asiatic types are few, and many of them have probably been carried over by the aborigines. The entire absence of gymnosperms is one of the notable features of the flora, as well as the low size of all the trees, none but the cocoa-nut palm exceeding 100 feet, the usual height of the largest trees being 50 or 60 feet. Nearly all the native plants are perennial and 1 HILLEBKAND, DR. WAILLIAMI.-Flora of the Hawaiian Islands: a description of their phanerogams and vascular cryptogams. Annotated and published after the author's death by W. F. Iillebrand. xcvi and 673 pp., with 8 maps, Svo.