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 such as chanced to come in direct and close contact with its little cell. United, they have formed vast islands, which have become the abode of man, and which, in the aggregate, form no inconsiderable portion of the globe.

The consideration of this leads us to perceive that God has ordained that units cannot, separately, accomplish much; and that united effort, in order to be successful, requires the harmonious action of units. "A house divided against itself cannot stand." The innumerable and eminently beautiful isles of the Pacific had never stood where they now stand if the curious, and separately insignificant, little architects that reared them had not wrought unitedly upon a fixed and systematic planeach insect working its utmost from the hour of its birth until that of its death.

There are various kinds of coral insects, which form varied species of coral rock. Some kinds of coral assume the form of rounded masses; some are like a branching shrub; others are in layers, or thin plates; and some are shaped like the human brain, from which they derive their namebrain-stones. These different kinds differ also in colour, and thus present a beautiful appearance when seen at the bottom of clear and shallow water.

In regard to the rate at which the corallines build their cells there is some diversity of opinionsome asserting that the process is imperceptible, while others state as positively that it is rapid. There