This volume reports recent studies of certain amines that have been found to be important in psychiatric states, particularly depression. Control of these amines, especially serotonin and nor-adrenalin, is effected by some of the drugs that affect the central nervous system. A Russian experimenter, Professor K. S. Koshtoyants of Moscow State University, reports an interesting observation: a dog was conditioned to show neurotic manifestations when subjected to various stimuli in an observation chamber. Later the dog gave birth to a litter of pups. When the dog was placed in the chamber with the pups, it no longer was subject to neurosis. This immunity lasted throughout the period of suckling. It was also found, however, that flow of milk was inhibited in the chamber. Koshtoyants cites this example as showing that both 'neurohumoral factors in the subcortical region' and hormonal factors produced the result.