As a result of the more recent developments and greater interest in immunology there has apparently been an overemphasis of this factor in the consideration of disease. I do not deny the importance of bodily resistance and of the virulence of infection, but I do maintain that these have been given undue stress. As a result, in disease processes in general there has been a veering away from the mechanistic point of view. Too often, owing to this vitalistic view, there has not been proper appreciation of the part played by structure.Such terms as lack of resistance, virulence of infection, endocrine influence and exudative diathesis are frequently used when a closer study would reveal the prime importance of the anatomic features. Although anatomy was the earliest of the basic medical sciences, there still remains much to be done in providing a knowledge of the more minute structure. Many phases of the development of disease, its progress, the causation of symptoms and the rationale of treatment