[RETROSPECT.]
"Ce que nous connaissons est peu de chose; ce que nous ignorons est immense."
La Place.
We have now arrived at the close of this argument; we have taken a general survey of the fossilized relics of the various classes of the animal and vegetable kingdoms, and have explained the methods by which the inscriptions on these "Medals of Creation" may be deciphered.
But numerous as are the facts that have passed in review before us, and great as the accession of geological knowledge has been during the last fifty years, the data hitherto obtained are insufficient to elucidate many of the obscure pages of the earth’s physical history; and to future discoveries must be left the full interpretation of many phenomena as yet obscurely presented to us.
In vain we endeavour to penetrate the veil which shrouds from our view many of the mighty events that preceded the history of our race, for,—although the shades of colossal and unknown forms belonging to the remote ages of a past eternity obey the spell of the true magician Science,—yet of the innumerable beings which through countless centuries
"The Earth has gather’d to her breast again,
And yet again, the millions that were born
Of her unnumber’d, unremember’d tribes—"