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112 only be said that deduction from them furnishes, in the first place, inference that Mars is a living world, subject to an annual cycle of surface growth, activity, and decay; and shows, in the second place, that this Martian yearly round of life must differ in certain interesting particulars from that which forms our terrestrial experience. The phenomena evidently make part of a definite chain of changes of annual development. So consecutive, and, in their broad characteristics, apparently so regular, are these changes, that I have been able to find corroboration of what appears to be their general scheme in drawings made at a previous opposition. In consequence, I believe it will be possible in future to foretell, with something approaching the certainty of our esteemed weather bureau’s prognostications, not indeed what the weather will be on Mars,—for, as we have seen, it is more than doubtful whether Mars has what we call weather to prognosticate,—but the aspect of any part of the planet at any given time.

The changes in appearance now to be chronicled refer, not to the melting of the polar snows, except as such melting forms the necessary preliminary to what follows, but to the subsequent changes in look of the surface itself. To their exposition, however, the polar phenomena become inseparable adjuncts, since they are inevitable ancillaries to the result.