Clinical experiences give evidence that about the end of the fourth decade of human life, and sometimes earlier, a period begins which may be regarded as presenile age,1 and it is characterized by disturbances of the circulatory system besides many other alterations. The clinical symptoms of these disturbances are as follows: The blood pressure becomes higher on a constant level, and at the same time one finds various signs of cardiac incompetence, especially during physical work, such as increase in the pulse rate, precordial uneasiness and, sometimes, dizziness. The accommodative power of the blood pressure becomes unsteady, as demonstrated by its irregular fluctuation. Therefore, an investigation into the complicated mechanism of the origin of high blood pressure in persons of presenile age is justified. The problem is important, since it is connected with many interesting questions of disease in human beings.
The consideration of these questions may also bring