The continuance of life depends primarily on the provision, through the blood, of sufficient nutriment of proper character for all of the tissues and organs of the body. Deficiency in either quantity or quality will result at first in derangement of function and ultimately, if maintained, in alterations in structure. Tissues of highest organization will naturally suffer earliest and in greatest degree. The blood vessels are likely to be involved in the morbid process, in part directly from the irritating effects of circulating noxious matters, in part indirectly through the imperfect nutrient supply conveyed by the vasa vasorum. The result will be some form of vascular degeneration, namely, atheroma followed by calcification, or sclerosis, or hypermyotrophy, or a combination of several or all. Arteriosclerosis is a common association of chronic nephritis, of which, it appears, it may be cause or effect or concomitant. Old age, excessive muscular activity and various