Long ago, Hippocrates, revered founder of the art of medicine, recognized that there was a specific affinity of disease for individuals with more or less the same characteristic somatic and psychic traits and trends. Tuberculosis, for instance, was noted for its frequency in long-skeletoned, thin persons, remarkably optimistic. And the plethoric, choleric nature of the sufferer from gout has become proverbial. Before the era of the great bacteriologic discoveries of the eighties and nineties, the concordance of esoteric racial and personal markings was a great help in diagnosis to the physician. For he realized, though he sometimes credited it to his clinical intuition, that it was a certain type of personality that was liable to the specific disease. But personality and its reactions, normal and abnormal, are determined by the endocrines. So we should find that particular infections run with special internal glandular predominances. For the picture presented by an infection, temperature, rash, prostration, are the details of the general reaction of the organism in the face of a new situation, the presence of a powerful, destructive invader. Information has accumulated that the invader is powerful and destructive, as well as selective, because of endocrine deficiency of one sort or another in the body it has attacked. Work of a number of investigators has indicated that an individual's susceptibility or its reverse, resistance, is intimately subjected to the derangements or harmonies of the endocrine system. Comparison of the endocrine type and the disease assaulting has yielded an even more interesting principle. Knowing the state of the internal secretion reservoirs enables us to predict the liability to certain of these infections of childhood. Diphtheria has been found to occur most virulently among adrenal poor individuals. Moreover, they are left poorer in adrenal afterwards. It follows that they would be assisted by the feeding of adrenal. Mumps is a sickness that sometimes permanently injures the gonads: the testes or ovaries. The thyroid dominant, whose system is rich in thyroid, will rarely suffer from any of the common diseases of children--if at all, from measles. Op the other hand, those who have every infection of the period, and who, as their mothers say, seem to get everything, are those whose system is thyroid poor. Thyroid poverty is a splendid enticement to the universal microbe. The thymocentric stands all diseases poorly. The pituitary type is more liable to epidemic meningitis and infantile paralysis, typhoid and scarlet fever.