Marantic thrombi are those whose origin is attributable to that enfeebled condition of the body known as marasmus. This represents a weakening of the several functions, especially the circulation, respiration, and locomotion. Such may take place in disease or old age; and it is important to bear in mind those diseases in which marasmus is likely to arise, as thrombosis often proves a complication of such affections. Protracted fevers, as typhus and typhoid, puerperal diseases, the disturbances following surgical operations, chronic wasting diseases, as the tuberculous and scrofulous affections, are all likely to be accompanied by thrombosis. Stagnation of the blood, as well as alterations of the intima, is an important local condition in this variety of thrombosis, which is usually valvular or parietal at the outset, and may be both arterial and venous. Such thrombi are likely to become continued and to serve as a frequent source of embolism. Thrombi are also divided into primitive, or autochthonous, and secondary varieties. The primitive thrombus is one which owes its local origin to conditions existing at the place of its formation and attachment. The secondary variety demands for its existence a primitive thrombus, whose place of development is remote in time and seat, and from which a part has been transferred to serve as the nucleus for the secondary formation. The continued thrombus is often confounded with the secondary variety. Continuance is rather a quality of all thrombi, and is essentially growth, whether by lamellation or agglomeration. Such continued thrombi are extended in the course of the circulation, usually by a conical end, which is pointed toward the heart in the case of venous thrombi, but away from this organ when the thrombi are arterial. Parietal and obstructing thrombi form another subdivision. The former arise from a limited part of the wall of the heart or blood-vessel, and project into its cavity. They are always in contact with flowing blood, and are white or mixed in color and primitive. They may attain a considerable size, and may eventually become obstructing thrombi. The latter are so called when they are of sufficient size to cause a considerable or total obstruction to the current of blood. In the last case the vascular canal is wholly filled by the thrombus. The shape of the older parietal forms is usually globular or pedunculate, owing to the growth in all directions except at the place of attachment; the obstructing thrombi are elongated.