September 20, 1917] 



NATURE 



57 



the Master of BalHoI. Longmans and Co. — Educa- 

 tion : Selective, Specific, Compensatory, M. West; 

 The Education of the South African Native, C. T. 

 Loram. Macmillan and Co., Ltd. — Problems- of the 

 Self : an Essay based on the Shaw Lectures given in 

 the University of Edinburgh, March, 1914, Prof. John 

 Laird ; Logic as the Science of Pure Concept, trans- 

 lated from the Italian of Benedetto Croce, by D. 

 Ainslie ; The Philosophy of Benedetto Croce : the 

 Problem of Art and History, Dr. H. W. Carr ; Brah- 

 madarsanam, or Intuition of the Absolute : Being an 

 Introduction to the Study of Hindu Philosophy, Sri 

 Ananda Acharya. John Murray. — Rustic Sounds, and 

 other Studies in Literature and Natural History, Sir 

 F. Darwin. Open Court Company.— System of 

 Morals founded on the Laws of Nature, M. Deshum- 

 bert. Seeley, Service and Co., Ltd. — ^Modern Whaling 

 and Bear-Hunting : A Record of Present-day Whaling 

 with Up-to-date Appliances in many Parts of the 

 World, and of Bear and Seal Hunting in the Arctic 

 Regions, W'. G. Burn Murdoch, illustrated. 



Philosophy and Psychology. 



Methuen and Co., Ltd. — Telepathy, Genuine and 

 Fraudulent, W. W. Baggally, with a preface by Sir 

 Oliver Lodge; The Science of Power, B. Kidd; From 

 the Watch Tower : or Spiritual Discernment, S. T. 

 Klein. 



Technology. 



Constable and Co., Ltd. — Wool, F. Ormerod, illus- 

 trated; Cotton, C. Bigwood, illustrated (Staple Trades 

 and Industries). Sir Isaac Pitman and Sons, Ltd. 

 — Glass and Glass Manufacture, P. Marson, illus- 

 trated; Gums and Resins, E. J. Parry, illustrated 

 (Commercial Commodities. of Commerce Series). 



EXPLORATIONS IN THE HAWAIIAN 



ISLANDS. 



pROF. A. S. HITCHCOCK, of the U.S. National 



^ Museum, and his son, travelled recently in the 



Hawaiian Islands, studying the flora, especially with 



reference to the grasses, making what might be termed 



a forage survey. 



The islands visited were Kauai, Oahu, Lanai, Molo- 

 kai, Maui, and Hawii. They are all of volcanic origin 

 and composed of lava, except a very small part, which 

 is of coral formation. Kauai, geologically the oldest 

 island, shows the greatest effect of erosion, its deep 

 canyons rivalling the beauty of the Grand Canyon of 

 Colorado. The rainfall on the mountains of the wind- 

 ward side is excessive, that of Waialeale, the highest 

 peak of Kauai, being as much as 600 in. per annum. 

 But the lee side of the islands is arid, the rainfall being 

 often reduced to fewer than 15 in. per annum. 



To the south the islands are successively younger, 

 Hawaii, the largest, being even now in a state of 

 volcanic activity. On this island are situated the two 

 highest peaks of the group, Mauna Kea, 13,825 ft., and 

 Mauna Loa, 13,675 ft. in height. There is scarcely 

 any vegetation upon these peaks, above 10,000 ft., 

 especially upon Mauna Loa, which is made up of com- 

 paratively recent lava. Much snow covers the peaks 

 in winter, extensive banks persisting throughout the 

 vear. The magnitude of the mountain mass is greater 

 than at first appears, because the cones arise from the 

 very fioor of the ocean, 18,000 ft, below the surface, 

 thus making the total height mpre than 30,000 ft. So 

 gtadual is the slope from the sea to the summit that 

 the eye is deceived and the great height is not at first 

 fully appreciated. The active volcano, Kilauea 

 (4000 ft.), with its pit of boiling lava, is on Hawaii, 

 while Haleakala, said to be the largest crater in the 

 world, is on Maui, the second largest island of the 

 group, 



NO. 2499, VOL. 100] 



Important agricultural industries of the island in- 

 clude sugar, live stock, and pineapples. The native 

 Hawaiian population is decreasing, and it is only in 

 the less accessible parts of the islands tHat the primi- 

 tive customs still prevail. Here may be found the 

 native grass huts made of a wooden framework filled 

 in with a thatch of grass. The grass used for this 

 purpose is usually pili {Heteropogon contortus), an 

 indigenous grass, abundant upon the rocky soil of the 

 lowlands. 



The introduced flora is very noticeable near towns, 

 ranches, and plantations, and one must go several 

 miles from Honolulu to find indigenous or native 

 plants. Of sixty species of grasses found on Oahu, 

 about fifty were introduced from foreign countries. 

 One of the introduced trees of great economic import- 

 ance is the algaroba tree {Prosopis juliflora) or kiawe, 

 as the Hawaiians call it. It is found in a belt on the 

 lowlands along the shores of all the islands, and occu- 

 pies the soil almost to the exclusion of other plants. 

 The pods are very nutritious, and are eagerly eaten by 

 all kinds of stock. Its flowers furnish an excellent 

 quality of honey. The Molokai ranch alone produces 

 150 to 200 tons of strained honey per year. The prickly 

 pear cactus {Opuntia tuna) has become extensively 

 naturalised in the drier portions of all the islands. 

 Two introduced shrubs, Guava and Lantana, now 

 occupy extensive areas, and have become great pests. 

 In the moister portions of the islands large areas have 

 been occupied by Hilo grass, which has little value as a 

 forage plant. The kukui, or candlenut, tree {Alcurites 

 moluccana), with its light, almost silvery, green foliage 

 is now a common and rather striking element in the 

 valleys and gorges. 



The indig(5nous flora is highly interesting, though 

 not abundant in species. Two of the commonest trees 

 are the ohia {Matrosideros polymorpha) and the koa 

 (Acacia koa). The former, also called ohia lehua and 

 lehua, resembles, in the appearance of the trunk, our 

 white oak, but bears beautiful clusters of scarlet flowers 

 with long, protruding stamens. The koa produces a 

 valuable wood much used in cabinet-making. Char- 

 acteristic of the upper forest belt on the high mountains 

 of Hawaii is the mamani (5o/)hora chrysophylla), a legu- 

 minous tree with lon^, drooping clusters 6f yellow 

 flowers and long, four-wmged pods constricted between 

 the seeds. In the arid regions is found the wiliwili 

 (Erythrina nionospertna), a deciduous tree with gnarly 

 giowth. Its bare branches are conspicuous, j^s decidu- 

 ous trees are unusual in the tropics. It has very soft 

 light wood, and bright scarlet seeds. Among the pecu- 

 liar plants of the islands is the silversword {Argyroxi- 

 phiunt sandwicense), a strikingly beautiful composite 

 with glistening silvery leaves, which grows only on 

 the slopes of cinder cones in the ciater of Haleakala, 

 and in a few very limited localities on Hawaii. The 

 family Lobeliaceaj is represented by about 100 species 

 belonging to six genera. The numerous arborescent 

 or tree-like species are very peculiar and characteristic. 

 Many of them form slender trunks like small palms, 

 crowned with a large cluster of long narrow leaves, 

 the trunks of some species being as much as 30 or 

 40 ft. high. 



The indigenous grasses of the Hawaiian Islands are 

 not numerous. A tall species of Eragrostis is the 

 dominant grass upon the plain between Mauna Loa 

 and Mauna Kea. Upon many of the summits of the 

 high mountain ridges in the regions of heavy rainfall 

 are found open bogs which support a peculiar and 

 interesting flora. Many species form more or less 

 hemispherical tussocks which rise above the general 

 level of the bog. A showy lobelia with numerous 

 large cream-coloured flowers as much as 3^ in. long, 

 peculiar violets,' and a sundew are found there. These 

 boggy areas are devoid of trees, and sometimes occupy 



