When the arterial tree becomes narrowed and the resistance offered to the flow of blood thereby is increased, more muscular work is required of the left ventricle and according to the general laws which govern muscles the ventricle hypertrophies. There is an actual increase in number of fibers as well as an increase in the size of the individual fibers. Some of the best examples of simple hypertrophy of the left ventricle are found under such circumstances. The chambers as a rule do not dilate until the resistance becomes greater than the contraction can overcome, when symptoms of broken compensation of the heart take place. The hypertrophy of the left ventricle brings more of this portion of the heart toward the anterior chest wall. The enlargement is toward the left, also, consequently the apex-beat is found below and to the left of its usual site, even an inch or more beyond the nipple line. The impulse is heaving, pushing the palpating hand forcibly up from the chest wall. The visible area of pulsation may occupy three interspaces and the precordium is seen to heave with every systole. On auscultation the second sound at the aortic cartilage is ringing, clear, and accentuated. Not infrequently, too, the first sound is loud and booming, but has a curious muffled sound that may even be of a murmurish quality. The leaflets of the mitral valve may be the seat of sclerosis, the edges are slightly thickened and do not quite approximate, thus causing a definite murmur with every systole. This murmur may be transmitted out into the axilla and be heard at the inferior angle of the left scapula. =Palpable Arteries= Not every artery that can be felt is the subject of arteriosclerosis, and, as has been stated, palpable arteries being more or less a condition of advancing years, judgment as to whether the artery is pathologically or physiologically thickened may be a matter of individual opinion. A radial artery that lies close to the lower end of the radius and can actually be seen to pulsate when the hand is held slightly extended on the back of the wrist, is easily felt, but must not, therefore, be considered a sclerosed artery. The radial may be so deeply situated in the wrist of a fat subject that it is difficultly palpable. Yet the two cases just described may have arteries of identical structure, there being no more retrogressive changes in the one than in the other. "Experience is fallacious and judgment difficult." The small, contracted, wiry artery of a chronic nephritic may feel like a pipe stem, but if properly felt the mistake will not be made of considering such an artery an unusually sclerosed one. When the wave is pressed out of such a high tension artery, it is found that what seemed to be a firm sclerosed vessel, was in reality an artery tightly stretched over the column of blood. =Ocular Signs and Symptoms=