Agno has 11 feet of water on its bar at high tide, which gives some importance to the port of Dagupan at its mouth. The Pasig is only 12 miles long, but as it connects Bay Lagoon (q.v.), or Laguna de Bay, with Manila Bay through the chief port of the island, it is a commercial highway of importance. The river systems of Mindanao, confined within the parallel ranges, have chiefly a north and south direction and are more important for navigation than those of Luzon. The Rio Grande de Mindanao, one of the largest rivers in the Philippines, drains the central basin of the island, carries the waters of many tributaries to the Celebes Sea on the west coast, and is navigable for gunboats as far as Lake Lagusan. The Rio Agusan (q.v.) rises about 25 miles from the south coast, and reaches the sea on the north coast, nearly dividing the island. It is navigable for a few miles from its mouth. The most important lakes in Luzon are: Laguna de Bay, 25 miles long and 21 miles wide, which receives numerous small streams from the mountains around it, and Bombon, 14 by 11 miles in extent, Taal volcano rising amid its waters. The largest lakes of Mindanao are Maguindanao, in the centre, and Malanao, near the north coast. Smaller lakes are scattered over the islands.
Climate. As the archipelago is wholly within the tropics, the climate is naturally very warm. From November to February inclusive, the most temperate months, the temperature ranges from 75° to 80° F. The hottest months are April, May, and June, when the monthly mean ranges between 81° and 83°. The intermediate temperatures are in March, July, August, September, and October, when the mean is from 79° to 81°. The temperature at Manila rarely rises above 100° in the shade, and does not fall below 60°. The prevailing atmospheric humidity intensifies the discomforts of heat, from which there is little relief in the three hottest months; but in December, January, and February the nights are fairly cool. As the mean temperature for the year varies merely by a few degrees, only two seasons are recognized. In the wet season, from June to October, five months, the rains are very heavy in the interior and on the west coast, because the moist southwest monsoon there prevails. The east coasts do not share in the excessive precipitation, because they are shielded by the mountains. In the dry season, from November to May, the comparatively dry northeast monsoon prevails, there are many, fair days, and the precipitation is greatest on the east coast. The rivers often overflow their banks during the wet season and wide areas in the larger islands are submerged; but the floods arc not feared so much as the cyclonic storms of wind and rain known as typhoons, which seldom occur south of 9° N. latitude, but north of that line sometimes destroy the lives of thousands of persons and wreck many vessels and villages. Cyclones are most frequent in July, August, September, and October, when these whirling winds from the Pacific occasionally sweep the whole archipelago north of Mindanao. The most terrific of these storms recorded in the Philippines struck Manila in 1882, traveling at a velocity of 140 miles an hour.
The danger from epidemic diseases is not great except for the occasional visitations of cholera, which is difficult to control, as has been proved since the United States acquired the islands. Smallpox is always prevalent, but very seldom attains wide-spread development. The bubonic plague has never gained a strong foothold, though in 1901-02 the most strenuous efforts were required to suppress it. Malaria is prevalent in some islands, especially Mindoro, Balabac, and parts of Palawan, Luzon, and Mindanao, but large districts are entirely free from it. Malarial fevers and digestive troubles are the chief diseases. On the whole the health of the natives is fairly good, but the climatic conditions, except in some districts, are not favorable to long residence by Americans or Europeans. It is fortunate that some places among the mountains afford health resorts to which white persons may go for recuperation. Such an asylum is the elevated plateau of the small province of Benguet, 150 miles north of Manila, where, during the hottest month of the year, the temperature is not over 70° F. at midday.
Flora. The vegetable life is rich and varied, with very few distinctive species, but some plants that are transitional between the flora of Formosa on the north and Borneo on the south. Sixty species of large trees afford the most valuable hard woods for the use of the ship-builders and cabinet-makers. Many other trees are so hard that they cannot be cut by the ordinary circular saw. The bamboo grows in numerous varieties, and, as in other parts of the Malayan Archipelago, is indispensable to the natives. The cocoa palm flourishes everywhere and many of the ripe nuts are collected in rafts and floated to market. The oil is used in cooking and as an illuminant. Other palms are very numerous. The banyan is common and grows to enormous dimensions, and the cinnamon, clove, and pepper are found wild in the southern islands. About 1200 genera and 5000 species of plants have thus far been recognized by botanists. Economically the most valuable of the wild plants is Manila hemp, the fibre of a wild plantain (Musa texilis). The plant closely resembles the edible banana in appearance and grows best on shaded hillsides at moderate elevations. The export crop is raised on plantations, which yield, when carefully managed, an annual return of 30 per cent. on the capital invested. This fibre is not successfully raised elsewhere except on a few plantations in North Borneo. Practically all the cultivated plants of the South Asian island world are successfully raised, including rice, sugar, tobacco, coffee, cacao, maize, and sweet potatoes.
Fauna. The islands are poor in indigenous mammals. The most important animal is the carabao or water buffalo, which is caught young, tamed, and universally employed as a draught animal, while his tough flesh is valued by the natives as meat. He is usually docile, but is slow and lazy and during the heat of the day will not work more than two hours at a time without his mud bath. The female gives abundant milk, from which ghee, a kind of butter is made. The hide makes valuable leather. The timarau, a small buffalo living in the jungles of Mindoro, has never been tamed; it often attacks and kills the larger carabao. A small humped variety of cattle are raised in large numbers for beef on some of the islands. Goats are common and are utilized both for milk and flesh. There are several species of deer, and both wild and domesticated hogs are very abundant. The larger horse as known in America and Europe, does not thrive, but the Philippine
