We now return to the consideration of material evolution through the Rounds. Matter in the Second Round, it has been stated, may be figuratively referred to as two‐dimensional. But here another _caveat_ must be entered. This loose and figurative expression may be regarded—on one plane of thought, as we have just seen—as equivalent to the second characteristic of matter, corresponding to the second perceptive faculty or sense of man. But these two linked scales of evolution are concerned with the processes going on within the limits of a single Round. The succession of primary aspects of Nature, with which the succession of Rounds is concerned, has to do, as already indicated, with the development of the Elements—in the Occult sense—Fire, Air, Water, Earth. We are only in the Fourth Round, and our catalogue so far stops short. The order in which these Elements are mentioned, in the last sentence but one, is the correct one for Esoteric purposes and in the Secret Teachings. Milton was right when he spoke of the “Powers of Fire, Air, Water, Earth”; the Earth, such as we know it now, had no existence before the Fourth Round, hundreds of millions of years ago, the commencement of our geological Earth. The Globe, says the Commentary, was “_fiery, cool and radiant, as its ethereal men and animals, during the First Round_”—a contradiction or paradox in the opinion of our present Science—“_luminous and more dense and heavy, during the Second Round; watery during the Third_.” Thus are the Elements reversed. The centres of consciousness of the Third Round, destined to develop into humanity as we know it, arrived at a perception of the third Element, Water. If we had to frame our conclusions according to the _data_ furnished us by Geologists, then we would say that there was no real water, even during the Carboniferous Period. We are told that gigantic masses of carbon, which existed formerly spread in the atmosphere, as carbonic acid, were absorbed by plants, while a large proportion of that gas was mixed in the water. Now, if this be so, and we have to believe that all the carbonic acid which went to compose those plants that formed bituminous coal, lignite, etc., and went towards the formation of lime‐ stone, and so on, that all this was at that period in the atmosphere in gaseous form, then, there must have been seas and oceans of liquid carbonic acid! But how then could the Carboniferous Period be preceded by the Devonian and Silurian Ages—those of fishes and molluscs—on that assumption? Barometric pressure, moreover, must have exceeded several hundred times the pressure of our present atmosphere. How could organisms, even so simple as those of certain fishes and molluscs, stand that? There is a curious work by Blanchard, on the Origin of Life, wherein he shows some strange contradictions and confusions in the theories of his colleagues, and which we recommend to the reader’s attention.