=Cadaveric Lividity.=—This means the black and blue discoloration from the effects of the congestion or contusion of the blood. After life becomes extinct, and before the blood coagulates, it changes its position chiefly in two ways: First, it is driven by their contraction out of the arteries and into the veins; second, it settles in the veins and the capillaries of the more dependent parts of the body, inducing, usually within a few hours after death, a mottling of the surface with irregular livid patches. These patches may coalesce, forming a uniform dusky red color over the back of the trunk, head and extremities, and sometimes over the ears, face and neck. The same effect is noticed on the anterior aspect of the body if it has lain on the face. At points of pressure, from the folds in the clothing, and from the weight of the body on the bed or the cooling board, the red color is absent or less marked. This to the undertaker and the embalmer is known as postmortem discoloration. These changes occur before putrefaction sets in. This cadaveric lividity should not be mistaken for the antemortem ecchymoses from which it may usually be distinguished by its position and extent by the fact that the surface of the skin is not elevated, and by the fact that on incision no blood is found free in the interstices of the tissues. Not infrequently the subcutaneous tissue in the neighborhood of these postmortem discolorations become infiltrated with a reddish serum. Very soon after death, particularly in warm weather, the tissues immediately around the subcutaneous veins of the neck and the thorax and in other situations, may become stained a bluish red color from the decomposition and escape from the vessels of the coloring matter of the blood. This to the undertaker and the embalmer is known as postmortem discoloration. =Putrefactive Changes.=—As soon as the body dies, it becomes as any other inanimate object, subject to putrefaction and decay. The tissues of the body undergo various changes as to consistency of the solids, semi-solids, fluids, and as to color. Putrefactive changes are caused by the presence of putrefactive germs normally present in the tissues or gaining access to them, which in their effort to satisfy their own nutrition, break down those complex molecules of which the tissues are composed into simpler compounds. Putrefaction then is organic decomposition or decay the result of putrefactive bacteria. Putrefaction may also be defined as the separating of the constituent elements of the body due to the presence and growth of bacteria. Although septic changes may take place before the death of a body, yet the term putrefaction is not applied until after the death of a body, and denotes those changes in color, consistence, and smell so clearly perceptible.