As was to be expected, the discovery of the nervous apparatus of the salivary glands immediately impelled physiologists to seek a similar apparatus in other glands lying deeper in the digestive canal.

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.

Do not become archivists of facts. Try to penetrate to the secret of their occurrence, persistently search for the laws which govern them.

While you are experimenting, do not remain content with the surface of things.

Appetite, craving for food, is a constant and powerful stimulator of the gastric glands.

As we have seen, bread, and especially dry bread, evokes secretion of considerably larger quantities of saliva than meat.

Don't become a mere recorder of facts, but try to penetrate the mystery of their origin.