The =Guayas= is undoubtedly the most important river system on the entire west coast, and the only one admitting much navigation. It drains and irrigates a large region, 14,000 square miles, between the great Andes and the low coastal hills. This section has been called the most fertile belt of tropical America. Below the Island of Puná, the river is lost in the Gulf; above, it has much the character of an estuary up to the city of Guayaquil, 33 miles, where it has a width of more than a mile. Not far above the city, the river loses its name at the confluence of the Daule and Bodegas. These two have other names, as do their tributaries also. The principal branches of the Bodegas, which is known also as the Babahoyo, are the Yaguachi or Chimbo, the Vinces or Quevado, and the Calamara or Sapotal; the Daule farther west, also called the Balzar, is about 130 miles long, not counting its windings. In its upper part it receives the Grande and Peripe Rivers, and lower down a number of streams and _esteros_ or canals. CLIMATE The climate of the several sections, as in Colombia and Venezuela, varies chiefly on account of the altitude, though in places affected also by other causes obvious or hidden. The coastal region is warm with a mean temperature of 82.4°, but with variation in humidity and rainfall. South of the equator the coast is arid with little rain, except in the vicinity of the Gulf of Guayaquil; but farther north in the Province of Esmeraldas there is rain and luxuriant vegetation, as along the Colombian littoral. Towards the mountains, the climate though warmer is agreeable in the dry season. The mountains which approach the shore of the Gulf of Guayaquil condense the moisture of the trade winds from the east, causing plenty of rain, sometimes too much; the humidity is excessive. Guayaquil, average temperature 80°, has been notoriously unhealthful. The condition, however, was due more to lack of sanitation than to the climate itself. We know of the wonderful change at Panamá; but at Guayaquil, partly no doubt because of several revolutions and financial difficulties, yellow fever and other diseases have long been prevalent. Happily yellow fever was eradicated under the supervision of General Gorgas, but bubonica and small pox may still exist. Recently contracts have been placed for sanitation, sewers, paving, and other improvements, and something is already accomplished. In some sections there are two rainy and two dry seasons a year, in others it is liable to rain at any time. At Guayaquil the rainy season is from December to April inclusive, or longer, the remainder of the year being dry. In Ecuador the dry season though the cooler is called _verano_ or summer, while the warmer rainy months are called _invierno_ or winter.