States with the reports for the time during which they have been engaged in active service in the Philippines. While it may be predicted with confidence that the carrying out of the plans of the well-organized Department of Public Health will tend to a general improvement in sanitary conditions, it will doubtless remain true that troops that are obliged to campaign in the damp lowlands or garrison towns which have sprung up in situations where towns should never have been built, will suffer more or less. The change made in the sanitary conditions of Santiago de Cuba, Havana, and other Cuban towns, as well as the revolution effected in Porto Rico, and the surprising and almost incredible decrease in the mortality statistics, show what may be done in hot countries toward improving the health conditions of places that in the past have been considered the plague spots of the earth.

Modern science and invention have robbed the Tropics of most of their discomforts and many of their dangers, so that people from the temperate zones are now living there with comfort and health, as can be seen in India, where Englishmen are engaged in all sorts of enterprises.

In the treatment of diseases peculiar to tropical lands it is well known that a suitable change of climate is often more effective than any drugs. that can be administered. Recuperation from severe wounds or wasting diseases is slow in low altitudes and the long experience of the British in India, the Dutch in Java, and our own brief experience in the Philippines have shown that an occasional change to a cooler climate is very desirable, even for those who live in the more healthful parts of the Archipelago. Especially is this true of white children, who usually do very well up to the age of 8 or 10 years and then seem to require a change.

Chapter V.

FLORA.

[By Elmer D. Merrill.]

Colonial Botanical Gardens-Recognition of need of work on the flora of the Philippines by the Civil Commission-The richness of the flora-Striking characteristics of the flora-The relationship with surrounding countries-The flora increased by species introduced from Malaya and America-Our present lack of knowledge of the flora-Botanical regions in Luzon, Mindoro, Paragua, and the southern islands-The classification of the typical vegetative areas-Littoral vegetation: Mangrove, tidal, strand-Bamboo jungles-Savannahs-Deserted clearings-The higher mountains-The vegetation in the vicinity of towns: Trees, shrubs, herbaceous plants-The forest regions.

In the colonial possessions of Great Britain and Holland the fact that an accurate knowledge of the flora of the country is the first essential for future sucessful agricultural and forestry work was realized in the beginning of their colonial administration and, consequently, there are to be found in Java, Hongkong, Singapore, Penang, Ceylon, and India long-established botanic gardens, each with magnificent collections of growing plants, both native and foreign, large herbaria, and complete botanical libraries. In all these institutions the primary object has been to study and classify the flora of the several countries and, secondly, to inquire into the economic, agricultural, and forestry problems. This primary work has now been accomplished, and these institutions, thus thoroughly grounded, are working on economic questions pertaining to agricultural and timber industries.

In the Philippines this same principle finally came to be recognized, but not until after several centuries of occupation. The Spaniards had, however, done much toward developing a botanical knowledge of the plants of the Archipelago, but the invaluable collections and hardly less valuable library were destroyed by fire prior to American occupation, causing a loss that will take years to replace. A botanic garden in the Philippines is a matter of such great importance to the agricultural interests of the Islands that the question has received the serious consideration of those directly interested, and it is thought that before long a site will be selected where scientific work on timber, fiber plants, fruits, medicinal plants, food plants, and those that produce dyes, tans, gums, resins, gutta-percha, etc., can be carried on to the material benefit of every inhabitant of the Islands.

The botany of the Philippines has not received the attention from scientists that has been devoted to the fauna, and whatever attention has been paid to the vegetation has been directed to its economic rather than scientific features.

The importance of a more thorough knowledge of the flora of the Archipelago was recognized by the Philippine Commission, and in February, 1902, the position of botanist was provided for in the Bureau of Agriculture. In July, 1902, the botanical work of the Forestry Bureau was united with that of the Agricultural Bureau and in July, 1903, all botanical work, herbarium, botanical books, and equipment was transferred to the Bureau of Government Laboratories. In this Bureau a thoroughly equipped botanical laboratory is being organized, with a complete botanical library and working herbarium, and in the near future it is hoped that the work can be extended from purely systematic botany to all lines of botanical investigations; and that the laboratory may become the objective point of those American botanists. who may wish to pursue investigations on a tropical flora.

Like that of all tropical countries where there is an abundant rainfall, the flora of the Philippines is very rich. Comparatively speaking, little is known regarding the flora of the Archipelago, other than the more common species and those of economic value. So far as the flora has been worked out the most striking characteristics are the very large per cent of endemic species and the very few endemic genera. Of the 4,500 species of plants from the Archipelago at present known over 1,200 species are endemic, while but seven genera are endemic. It is very probable, however, that this number of endemic genera will be increased as our knowledge of the flora is perfected. It is probable that there are at least 8,000 species of phanerogams and vascular cryptogams in the Philippines at the present time, and one prominent worker on the flora of this region is of the opinion that eventually at least 10,000 species will be found here. At present, as noted above, only about 4,500 species have been reported from the Archipelago, probably about one-half of the number of species indigenous to the Islands. Thorough botanical collections have been made only in certain localities in the Island of Luzon, and our knowledge of the flora of the southern islands is exceedingly limited, while from many islands, and from most of the high mountains in the group, no botanical material has ever been collected. The 4,500 species at present reported from the Archipelago represent 151 families and about 1,100 genera.

The relationships of the Philippine flora with that of surrounding countries is a matter of great interest, and has been ably discussed by Mr. R. A. Rolfe, who points out the connecting links of our flora with that of Java, Sumatra, Borneo, the Moluccas, Celebes, Australia, Polynesia, Formosa, Southern China, and the Malayan Peninsula.

The flora of the Archipelago has been increased by the introduction of many species of economic or ornamental value from other tropical countries, many of which have become spontaneous and thoroughly naturalized. Before the Spanish occupation, during the successive Malayan invasions, many of the fruit-bearing trees and other plants of economic value were introduced from the Malayan Archipelago and British India, while after the Spanish occupation many American. species were purposely or accidentally introduced. At the present time about 60 species of American origin are found in the Archipelago, most of them having become spontaneous. The following plants of economic value are all of American origin: Tobacco, corn, potatoes, sweet potatoes, cacao, chico, maguey, guava, tomatoes, cassava, pineapple, peanuts, papaya, ciruelas, cashew nut, custard apple, chico-mamey, and other species.

At the present time our knowledge of the flora of the Archipelago is too limited to admit making any attempt to divide the Archipelago into botanical regions, although some work has been done on this subject by Rolfe, Vidal, and Christ.

The Island of Luzón, the botany of which is better known than that of any other island in the Archipelago, seems to present five fairly distinct botanical regions--the northern part of Luzón, the region between the Cagayan Valley and the Pacific coast, the Zambales region, extending from the Caraballo Sur Mountains to Laguna de Bay, and Southern Luzón, extending from the Province of Laguna to Albay. These five regions have many characteristics in common, and further study of the flora of the several regions may necessitate radical changes in this classification. All of these regions contain high, densely forested mountains, humid river valleys, and extensive areas of open grass lands.

Mindoro presents at least two distinct regions, the northern part.of the island, with a very heavy rainfall, no doubt caused by the presence of very high mountains, and characterized by a most luxuriant vegetation; while southern Mindoro has apparently much less rainfall, and is characterized by "thin" deciduous forests, and large areas of open grass land. Paragua, which connects the flora of the northern Philippines with that of Borneo, should prove an especially interesting field for investigation, but at present very little is known regarding its vegetation. Like the Island of Mindoro, it presents two very distinct regions, the northern part, characterized by continuous, dense forests, and the southern part, with much open grass land, with scattered trees, the forests only reaching a luxuriant growth on the higher mountains.

No data is at hand to even suggest a division of the other large islands of the Archipelago into botanical regions. With one or two exceptions, all of them contain both luxuriant forests and large areas of open land. From the little botanical material available from Mindanao, the second largest island in the group, it is evident that this island is the richest of

all in the Archipelago in the number of species and in the luxuriance of its vegetation.

From preliminary observations on the flora of the Philippines it is apparent that the scheme of classification of tropical vegetation proposed by Kurz, in his Forest Flora of British Burma, can not be applied to the vegetation of the Philippines without some radical changes. The distinction between evergreen and deciduous forests is not at all strongly marked in the Philippines. Mixed forests are decidedly predominant and moreover certain distinctive types of vegetation are found here which are not described by Kurz. An intelligent account of the many characteristic vegetative areas found in the Philippines can only be given after a thorough botanical investigation, covering all regions of the Archipelago-work that must necessarily extend over a period of years. Accordingly in the following account but two or three typical vegetative regions are discussed, and to this discussion is added some account of the vegetation found about most towns in the Archipelago, which may prove of interest to many American residents of the Archipelago.

LITTORAL VEGETATION.

Three classes of littoral vegetation can be readily distinguished, which may be designated as mangrove, tidal, and strand vegetation. The mangrove vegetation is found in the lowlands about the mouths of rivers, and is characterized by the peculiar habit of the trees making up the forest.

The Rhizophoracea.—Three genera are found in these forests-tangal (Rhizophora), bacauan or bacao (Ceriops, Brugiera, and Rhizophora), and ligason (Ceriops). These mangrove trees are valuable firewoods, and all yield tans and dyes. In the true mangroves little or no vegetation of other kinds is found, except a few epiphitic orchids, ferns, etc. Along the border of the mangrove swamp, and extending generally along the rocky seashores, are found pagatpat (Sonneratia Pagatpat Blanco), tingon baguis (Ægiceras corniculatum Blanco and A. florida R. and S.), tibigi or nigui (Xylocarus obovatum Juss., and X granatum L.), culasi (Lumnitzera purpurea Gaud.), pipisic (Avicennia officinalis L.), and other less. conspicuous species.

The tidal vegetation, which, strictly speaking, includes the abovementioned species, with the exception of the Rhizophoracea, would make an extended list, comprising only those species that grow within the influence of the salt water. Here we find such trees as dungon, late (Heritiera littoralis Dry.), nilac (Scyphiphora hydrophyllacea Gaertn.), dapdap (Erythrina ovalifolia), buta (Excoecaria agallocha), bignay (Antidesma sp.), balic balic (Pongamia glabra), bantigi (Pemphis acidula), butabuta (Cerbera Odollam), anonang (Cordia myxa), banalo (Thespesia populnea Corr.), mapola (Hibiscus tiliaceus), and calapinai (Dodonoea viscosa). Among the smaller shrubs found here may be mentioned dilauirio (Acanthus ilicifolius), lagundi late (Pluchea Indica, Clerodendron