scanned. For there turns out to be something at these junctions. This something shows itself as a round or oval spot. To such spot, planted there in the midst of the desert at the junction, do the neighboring canals converge.
Dotted all over the reddish-ochre ground of the desert stretches of the planet, the so-called continents of Mars, are an innumerable number of dark circular or oval spots. They appear, furthermore, always in intimate association with the canals. They constitute so many hubs to which the canals make spokes. These spots, together with the canals that lead to them, are the only markings to be seen anywhere on the continental regions. Otherwise the great reddish-ochre areas are absolutely bare; of that pale fire-opal hue which marks our own deserts seen from far.
That these two things,—straight lines and roundish spots,—should, with our present telescopic means, be the sole markings to appear on the vast desert regions of the planet is suggestive in itself.
Another significant fact as to the character of either marking is the manifest association of the two. In spite of the great number of the spots, not one of them stands isolate. There is not a single instance of a spot that is not connected by a canal to the rest of the dark areas. This remarkable inability to stand alone shows