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45 On the 21st I similarly suspected the Jamuna and the Nilokeras. Both looked broad and dusky, with very ill-defined condensation at the sides. But the seeing was not superlative. On the 22d I brought my observations to an end, in consequence of having to return East. Exactly what takes place, therefore, in this curious process of doubling I cannot pretend to say. It has been suggested that a progressive ripening of vegetation from the centre to the edges might cause a broad swath of green to become seemingly two. There are facts, however, that do not tally with this view. For example, the Ganges was always broad, but fainter, not narrower, earlier in the season. The Phison, on the other hand, went through no such process. Indeed, we are here very much in the dark, certainly very far off from what does take place in Martian canal gemination. Perhaps we may learn considerably more about it at the next opposition. At this the tendril end of our knowledge of our neighbor we cannot expect hard wood. To return now from these outposts of investigation to our main subject matter. We have seen what shows at one end of the canals, their inner end, namely, the oases. But it seems that there is also something exceptional at the other. At the mouth of each canal, at the edge of the so-called seas, appears a curious dark spot of the form of a half-filled angle; the sort of a mark with which one checks items on a list. Its form is singularly appropriate, according to mundane ideas, for it appears before the canal itself is visible, as if to mark the spot where the canal will eventually be. It lies in the so-called seas, and looks to be of the same color as they, but deeper in tint. All the canals that debouch into the dark regions are provided with these terminal triangles, except those that lead out of long estuaries, like the Nilosyrtis, the Hiddekel, the Gehon, and so forth. The double canals are provided with twin triangles. That the triangular patches are phenomena connected with the canals is evident from the fact that they never appear elsewhere. What exact purpose they serve is not so clear, but it would seem to be that of reservoirs or relay stations for the water before it enters the canals; what we see, upon this supposition, being not the station or reservoir itself, but the specially fertile area round it. That, in addition to being in a way oases themselves, they serve some such purpose as the above is further hinted at by two facts: first, that whereas the oases develop, apparently, after the canals leading to them, the triangular spots develop before the canals that lead out of them; second, Mr. Douglass finds that it is in them that the canals in the dark regions terminate. They are the end of the one system at the same time that they are the beginning of the other. They would, therefore, seem to be waystations of some sort on the road taken by the water from the polar cap to the equator. Paralleling in appearance the oases in the bright regions are round spots that occur at the junctions of the canals in the dark ones. Speaking figuratively, these are the heads of the nails in the coffin of the idea that the seas are seas; since, if the blue-green color came from water, there could not be permanent darker dots upon it connected by equally dark streaks. Speaking unfiguratively, this shows that the whole system of canals and specially