It goes without saying that the desire to accomplish the task with more confidence, to avoid wasting time and labour, and to spare our experimental animals as much as possible, made us strictly observe all the precautions taken by surgeons in respect to their patients.

Edible substances evoke the secretion of thick, concentrated saliva. Why? The answer, obviously, is that this enables the mass of food to pass smoothly through the tube leading from the mouth into the stomach.

The digestive canal represents a tube passing through the entire organism and communicating with the external world, i.e. as it were the external surface of the body, but turned inwards and thus hidden in the organism.

If we could look through the skull into the brain of a consciously thinking person, and if the place of optimal excitability were luminous, then we should see playing over the cerebral surface, a bright spot with fantastic, waving borders constantly fluctuating in size and form, surrounded by a darkness more or less deep, covering the rest of the hemisphere.

Science demands from a man all his life. If you had two lives that would not be enough for you. Be passionate in your work and in your searching.

But man has still another powerful resource: natural science with its strictly objective methods.

Possibilities are like the wings of birds; they allow man to soar and to climb to the heavens. And facts are like the atmosphere against which those wings must beat, and without which the soaring bird will surely plummet back to earth.