The general subject of diatheses in infancy and childhood is discussed. The rôle of inheritance in determining the constitution, predisposition and behavior of the child is considered to be of prime importance. Lesage believes that considerable information concerning the diathesis of the infant may be obtained from the cranial development and weight curve, even during the period immediately following birth. An original and simple classification of hereditary conditions consists of five divisions: (1) local inheritance, in which anomalies or morbid processes affect one organ or one system of the body; (2) inheritance of an infection, such as syphilis or tuberculosis; (3) inheritance of intoxication by alcohol, morphine, lead or other poison; (4) "explosive" inheritance, in which certain illnesses strike suddenly during later life, and (5) inheritance of arthritis.
The arthritic diathesis is discussed in detail with a consideration of the symptoms, general clinical course and treatment. The author speaks of