The crow, the deer, the eagle, &c., are all supposed to be long-lived. Some people have fancied that in their normal state they tended to a period of two[Footnote: I have heard the same normal duration ascribed to the tortoise, and one case became imperfectly known to myself personally. Somewhere I may have mentioned the case in print. These, at any rate, are the facts of the case: A lady (by birth a Cowper, of the whig family, and cousin to the poet Cowper; and, equally with him, related to Dr. Madan, bishop of Peterborough), in the early part of this century, mentioned to me that, in the palace at Peterborough, she had for years known as a pet of the household a venerable tortoise, who bore some inscription on his shell indicating that, from 1638 to 1643, he had belonged to Archbishop Laud, who (if I am not mistaken) held the bishopric of Peterborough before he was translated to London, and finally to Canterbury.] centuries. I myself know nothing certain for or against this belief; but, supposing the case to be as it is represented, then this would be the _aeonian_ period of these animals, considered as individuals. Among trees, in like manner, the oak, the cedar, the yew, are notoriously of very slow growth, and their _aeonian_ period is unusually long as regards the individual. What may be the _aeon_ of the whole species is utterly unknown. Amongst birds, one species at least has become extinct in our own generation: its _aeon_ was accomplished. So of all the fossil species in zoology, which Palaeontology has revealed. Nothing, in short, throughout universal nature, can for a moment be conceived to have been resigned to accident for its normal _aeon_. All periods and dates of this order belong to the certainties of nature, but also, at the same time, to the mysteries of Providence. Throughout the Prophets, we are uniformly taught that nothing is more below the grandeur of Heaven than to assign earthly dates in fixing either the revolutions or the duration of great events such as prophecy would condescend to notice. A day has a prophetic meaning, but what sort of day? A mysterious expression for a time which has no resemblance to a natural day--sometimes comprehending long successions of centuries, and altering its meaning according to the object concerned. 'A time,' and 'times,' or 'half a time'--'aeon_,' or '_aeons_ of _aeons_'--and other variations of this prophetic language (so full of dreadful meaning, but also of doubt and perplexity), are all significant. The peculiar grandeur of such expressions lies partly in the dimness of the approximation to any attempt at settling their limits, and still more in this, that the conventional character, and consequent meanness of ordinary human dates, are abandoned in the celestial chronologies. Hours and days, or lunations and months, have no true or philosophic relation to the origin, or duration, or periods of return belonging to great