“When thus constituted, it afforded a display of physical features of astonishing contrasts, and its mere scenic resources were doubtless of unparalleled splendor, and, as to-day, it was involved in the luxuriant productivity of the tropics. Its mountains measuring now as high as eleven thousand feet above the sea level, were then thrust upward into stupendous peaks, by the addition of the sloping miles which are now below the ocean. We can imagine the extreme wonderfulness of this continent, uniting in an unbroken but marvellously varied expression of physical and vegetable contrast, the plains, valleys, and mountains of Cuba, the towering and draped peaks of Jamaica, the confusion of the gloomy vales and ranges of Hayti and San Domingo, the levels and coastal ranges of Porto Rico, and the manifold picturesque charms of the Lesser Antilles, lifting high into the ceaseless currents of the trade winds the smoking summits of a chain of disturbed volcanoes. All, in the boundless abundance of its natural endowment of loveliness, and productivity, formed an unique and extravagantly ornamented landscape, an area whose highest elevations contemplated the remote waters of the shrunk Atlantic, from pinnacles raised ten to twenty thousand feet above its azure waves. Nor is this all. This hypothetical--the Columbian--continent, may have had connexions with Central America through projecting and peninsulated capes, reaching through Jamaica to Yucatan or Honduras, and wide intervals of dividing gulfs of water, in all probability sundered it from North or South America, and it remained, as I here emphatically insist, it remains to-day, a geographical and geological phenomenon, unrelated to the great continents, to which through their preponderating value, the mind almost unpremeditatingly assigns it. “But at the period of this greatest elevation, when this tropical region assumed individual independence, and embodied a geognostic importance comparable to the vast continents it lay between--at this time--the Isthmus of Panama did not exist, and through a wide water-way the Atlantic mingled its tides with those of the Pacific. “We are thus led to believe that as between the West Indian terranes and the neck of land now embraced in the Isthmus of Panama, we have a relation of _Isostacy_.’”