DAY AND NIGHT.
Day is a snow-white dove of heaven,
That from the east glad message brings:
Night is a stealthy, evil raven,
Wrapped to the eyes in his black wings.
Thomas Bailey Aldrich.
THE GEOLOGICAL SUCCESSION OF FISHES.
In discussing this subject it will be necessary to say something about the geological history of the earth. Each geological age had its own peculiar fauna, and to write about any part of it means that we must know something about the particular geological age in which the animals under consideration flourished, and something of the earth's previous history.