The endocrine glands play an enormous role in the life of the organism in general and in its neuropsychic activity in particular. The glands are in a certain interaction with each other (chemical correlation), their secrets mutually reinforce each other or neutralize; thus, the loss of one of these organs (resp. secrets) from the system or a change in their activity leads, in addition to the loss of a function specific to this organ, to a certain change in the entire system. The clinic gives us a whole series of examples confirming the propositions worked out by physiology.