Considering the multitude of streams and vastness of area drained by the Mississippi, it is natural to suppose the river is much affected in the stage of its water by the seasons. We have seen that the meltings of the Rocky Mountain snows, the mountain rills of the Alleghanies, the waters of the valleys of the upper river, of the Missouri, of the Ohio, the Arkansas, the Yazoo, and the Red, all find outlet through this one stream. There are certain seasons in the year when all these widely distant localities are subject to a gradual approach of warmth from the south, until they arrive at a sort of climatic average. This creates a maximum of the supply of water. The inverse then takes place, and a minimum results. For instance, in the latter part of December, the lower latitudes of the Mississippi begin to experience their annual rains. These by degrees tend northward as the season advances. In March commence the thaws of the southern borders of the zone of snow and ice; and during April, May, and June, it reaches to the most distant tributary fountain head. The river now is at its highest. The reverse then sets in. All the tributaries have their excess, the heats of summer are at hand, drought and evaporation soon exhaust the surplus of the streams, and the river is at its lowest. To meet the great annual excess of water in the Mississippi, nature has provided sure safeguards. These are termed bayous, and are found everywhere along the river, below the mouth of the Ohio. Additional preventives against inundation are the lagoons, or sea-water lakes, of the coast. Into these bayous and lagoons, as the river becomes high, the excess of water backs or flows. They are natural reservoirs, to ease the rise, and prevent the inevitable suddenness and danger which would result without them. In these reservoirs the water rises or falls with the river; and when the fall becomes permanent, the water in the bayous--the lagoons having outlet into the sea--falls with it, returning into the main stream, and finding entrance into the Gulf, from which it had been temporarily detained. Without the bayous the lands adjacent to the Lower Mississippi would, with very few exceptions, be subject to an annual overflow, and be perfectly worthless for certain agricultural purposes. In summer the bayous in numerous instances become perfectly dry, and give a very singular effect to the appearance of the country. Below the mouth of the Red River the tributaries of the Mississippi cease, and the entire volume of the river is attained. As a protection against serious consequences arising out of such an immense mass of water, nature has again introduced a remedy. This consists in a number of lateral branches, which leave the river a short distance below the mouth of the Red, tending directly to the Gulf, through a continuous chain of conduits, lakes, and marshes.