I call your special attention to Lamarck, because later on there were Neo-Lamarckians as well as Neo-Darwinians.  I was a Neo-Lamarckian.  Lamarck passed on from the conception of Evolution as a general law to Charles Darwin’s department of it, which was the method of Evolution.  Lamarck, whilst making many ingenious suggestions as to the reaction of external causes on life and habit, such as changes of climate, food supply, geological upheavals and so forth, really held as his fundamental proposition that living organisms changed because they wanted to.  As he stated it, the great factor in Evolution is use and disuse.  If you have no eyes, and want to see, and keep trying to see, you will finally get eyes.  If, like a mole or a subterranean fish, you have eyes and dont want to see, you will lose your eyes.  If you like eating the tender tops of trees enough to make you concentrate all your energies on the stretching of your neck, you will finally get a long neck, like the giraffe.  This seems absurd to inconsiderate people at the first blush; but it is within the personal experience of all of us that it is just by this process that a child tumbling about the floor becomes a boy walking erect; and that a man sprawling on the road with a bruised chin, or supine on the ice with a bashed occiput, becomes a bicyclist and a skater.  The process is not continuous, as it would be if mere practice had anything to do with it; for though you may improve at each bicycling lesson during the lesson, when you begin your next lesson you do not begin at the point at which you left off:  you relapse apparently to the beginning.  Finally, you succeed quite suddenly, and do not relapse again.  More miraculous still, you at once exercise the new power unconsciously.  Although you are adapting your front wheel to your balance so elaborately and actively that the accidental locking of your handle bars for a second will throw you off; though five minutes before you could not do it at all, yet now you do it as unconsciously as you grow your finger nails.  You have a new faculty, and must have created some new bodily tissue as its organ.  And you have done it solely by willing.  For here there can be no question of Circumstantial Selection, or the survival of the fittest.  The man who is learning how to ride a bicycle has no advantage over the non-cyclist in the struggle for existence:  quite the contrary.  He has acquired a new habit, an automatic unconscious habit, solely because he wanted to, and kept trying until it was added unto him.

HOW ACQUIREMENTS ARE INHERITED