Take one instance for our present purpose—the calculations of Mr. Croll. Whether, according to this authority, 2,500,000 years represent the time since the beginning of the Tertiary Age, or the Eocene period, as an American geologist makes him say;(22) or whether again Mr. Croll “allows fifteen millions since the beginning of the Eocene period,” as quoted by an English geologist,(23) both sets of figures cover the claims made by the Secret Doctrine.(24) For assigning as the latter does from four to five million years between the incipient and the final evolution of the Fourth Root‐Race, on the Lemuro‐Atlantean Continents; one million years for the Fifth, or Âryan Race, to the present date; and about 850,000 since the submersion of the last large peninsula of the great Atlantis—all this may have easily taken place within the 15,000,000 years conceded by Mr. Croll to the Tertiary Age. But, chronologically speaking, the duration of the period is of secondary importance, as we have, after all, certain American Scientists to fall back upon. These gentlemen, unmoved by the fact that their assertions are called not only dubious but absurd, yet maintain that man existed so far back as in the Secondary Age. They have found human footprints on rocks of that formation; and furthermore, M. de Quatrefages finds no valid scientific reason why man should not have existed during the Secondary Age. The Ages and periods in Geology are, in sober truth, purely conventional terms, as they are still barely delineated, and, moreover, no two Geologists or Naturalists agree as to the figures. Thus, there is a wide margin for choice offered to the Occultist by the learned fraternity. Shall we take for one of our supports Mr. T. Mellard Read? This gentleman, in a paper on “Limestone as an Index of Geological Time,” read by him in 1878 before the Royal Society, claims that the _minimum_ time required for the formation of the sedimentary strata and the elimination of the calcareous matter is in round numbers 600 million years;(25) or shall we ask support for our chronology from Mr. Darwin’s works, wherein, according to his theory, he demands for the organic transformations from 300 to 500 million years? Sir Charles Lyell and Prof. Houghton were satisfied with placing the beginning of the Cambrian Age at 200 and 240 millions of years ago, respectively. Geologists and Zoologists claim the maximum time, though Mr. Huxley, at one time, placed the beginning of the incrustation of the earth at 1,000 million years ago, and would not surrender a millennium of it.