diastinum

Updated: June 22, 2025

The internal coordination, like physiological adaptation, establishes itself as a result of the spontaneity of the exercises; the free development of a personality which grows and organizes itself is that which determines such an internal condition, just as in the body of the embryo the heart, in process of development, makes a place for itself in the space of the diastinum between the lungs, and the diaphragm assumes its arched form as a result of pulmonary dilation.

Maria Montessori - Spontaneous Activity in Education