During the course of a not yet completed quantitative study of the formed elements of the urine, notes have been kept in regard to the occasional occurrence of a certain type of cast whose most distinctive characteristic is a quite unusual breadth. This feature is illustrated in Figures 1 and 2, in which both these casts and ordinary hyaline casts are shown under the same magnification.
There are three distinct varieties of these broad casts, but they seem to be only different forms of the degeneration of a single type, since every stage of gradation from one variety to the other is often found in the same urine. The first variety, and the one from which the other two apparently develop, is a cellular cast in which even the nuclei of the cells can sometimes be distinguished. These cells are mononuclear, though occasionally two round or oval nuclei are seen