The small-mouth bass thrives only in comparatively clear, cool, and rocky or gravelly streams, and in lakes and ponds supplied by such streams or having cold bottom springs. In lakes of the latter character, in northern sections, it coexists with large-mouth bass in many instances. In such cases, however, the small-mouth will be found usually at the inlet, or about the springs, and the large-mouth at the outlet or in sheltered, grassy situations. In winter it undergoes a state of partial or complete torpidity. In ponds that have been drained in the winter season it has been found snugly ensconced in the crevices of rocks, beneath shelving banks, logs, roots, or among masses of vegetation, undergoing its winter sleep. In the spring, when the temperature of the water rises above fifty degrees, the small-mouth bass emerges from its winter quarters, about which it lingers until the water becomes still warmer, when it departs in search of suitable locations for spawning. At this time, owing to a semi-migratory instinct, it ascends streams, and roams about in lakes or ponds, often ascending inlet streams, or in some instances descending outlet streams. When favorable situations are found, the male and female pair off and proceed to fulfil the reproductive instinct. The spawning period extends from May to July, according to the section of the country it inhabits, and when the temperature of the water is suitable. The nests are formed on a bottom of gravel or coarse sand, or on a flat rock in very rocky streams. The male fish does the work of preparation by scouring with fins and tail a space about twice his length in diameter, forming a shallow, saucer-shaped depression, in which the female deposits her eggs, which are fertilized by the male, who hovers near by. The eggs are heavy and adhesive, being invested with a glutinous matter that enables them to adhere to the pebbles on the bottom. The number of eggs varies from two thousand to twenty-five thousand, according to the size and weight of the female. The nest is carefully guarded by the parents until the eggs hatch, the period of incubation being from one to two weeks, according to the temperature of the water. The resultant fry are then watched and brooded by the male fish for several days or a week, when they seek the shelter of weeds and grasses in shallow water.