the resemblance of the great continental regions of Mars to the deserts of the earth,—a solution of their character suggests itself at once; to wit, that they are oases in the midst of that desert, and oases not wholly innocent of design, for, in number, position, shape, and behavior, the oases turn out as typical and peculiar a feature of Mars as the canals themselves.
Each phenomenon is highly suggestive considered alone, but each acquires still greater significance from its association with the other; for here in the oases we have an end and object for the existence of canals, and the most natural one in the world, namely, that the canals are constructed for the express purpose of fertilizing the oases. Thus the mysterious rendezvousing of the canals at these special points is at once explicable. The canals rendezvous so entirely in defiance of the doctrine of chances because they were constructed to that end. They are not purely natural developments, but cases of assisted nature, just as they look to be at first sight. This, at least, is the only explanation that fully accounts for the facts. Of course all such evidence of design may be purely fortuitous, with about as much probability, as it has happily been put, as that a chance collection of numbers should take the form of the multiplication table.
In addition to this general dovetailing of
