as they can, and unravel themselves with a vast sense of relief.  Hence the longing to satisfy latent passions, with the fugitive pleasure in doing so.  But the external agencies that originally wound up that mainspring never cease to operate; every fresh stimulus gives it another turn, until it snaps, or grows flaccid, or is unhinged.  Moreover, from time to time, when circumstances change, these external agencies may encrust that primary organ with minor organs attached to it.  Every impression, every adventure, leaves a trace or rather a seed behind it.  It produces a further complication in the structure of the body, a fresh charge, which tends to repeat the impressed motion in season and out of season.  Hence that perpetual docility or ductility in living substance which enables it to learn tricks, to remember facts, and (when the seeds of past experiences marry and cross in the brain) to imagine new experiences, pleasing or horrible.  Every act initiates a new habit and may implant a new instinct.  We see people even late in life carried away by political or religious contagions or developing strange vices; there would be no peace in old age, but rather a greater and greater obsession by all sorts of cares, were it not that time, in exposing us to many adventitious influences, weakens or discharges our primitive passions; we are less greedy, less lusty, less hopeful, less generous.  But these weakened primitive impulses are naturally by far the strongest and most deeply rooted in the organism:  so that although an old man may be converted or may take up some hobby, there is usually something thin in his elderly zeal, compared with the heartiness of youth; nor is it edifying to see a soul in which the plainer human passions are extinct becoming a hotbed of chance delusions.

In any case each fresh habit taking root in the organism forms a little mainspring or instinct of its own, like a parasite; so that an elaborate mechanism is gradually developed, where each lever and spring holds the other down, and all hold the mainspring down together, allowing it to unwind itself only very gradually, and meantime keeping the whole clock ticking and revolving, and causing the smooth outer face which it turns to the world, so clean and innocent, to mark the time of day amiably for the passer-by.  But there is a terribly complicated labour going on beneath, propelled with difficulty, and balanced precariously, with much secret friction and failure.  No wonder that the engine often gets visibly out of order, or stops short:  the marvel is that it ever manages to go at all.  Nor is it satisfied with simply revolving and, when at last dismounted, starting afresh in the person of some seed it has dropped, a portion of its substance with all its concentrated instincts wound up tightly within it, and eager to repeat the ancestral experiment; all this growth is not merely material and vain.  Each clock in revolving strikes the hour, even the quarters, and often with lovely chimes.  These