The buttonwood throws off its bark in large flakes, which one may find lying at its foot, pushed out, and at last pushed off, by that tranquil movement from beneath, which is too slow to be seen, but too powerful to be arrested. One finds them always, but one rarely sees them fall. So it is our youth drops from us, — scales off, sapless and lifeless, and lays bare the tender and immature fresh growth of old age. Looked at collectively, the changes of old age appear as a series of personal insults and indignities, terminating at last in death.

Oliver Wendell Holmes, Sr. (1809-1894) American poet, essayist, scholar

Article (1858-05), “The Autocrat of the Breakfast-Table,” “Explicit Allegoria Senectutis,” Atlantic Monthly
    (Source)

Collected in Autocrat of the Breakfast-Table, ch. 7 (1858).