The mortality from plague may be about 90 per cent. or more when the epidemic is at its height. In the beginning, or towards the end of the epidemic, the mortality is less, as it is the case with all other epidemic diseases. The average mortality at Bombay has been 84 per cent. and in Karachi 89 per cent. It is, therefore, more fatal than all other epidemic diseases, the mortality from cholera during the height of an epidemic being about 60 per cent. In children and in the aged the disease is more fatal than in healthy adults. Cases in which the bubo appears early and is single, or in which there is a distinct morning remission, or less general prostration or free perspiration, or in which there is no diarrhœa, have greater chance of recovery. Rapid suppuration of the buboes indicates a favourable termination. Buboes do not suppurate as a rule until the primary fever has fallen. On the other hand, carbuncles, multiple buboes (specially on the neck), meningitis, hæmorrhages, pleurisy, pneumonia, diarrhœa, gastric irritation, cyanosis, jaundice and continued pyrexia are unfavourable signs. _MICROSCOPIC AND MACROSCOPIC APPEARANCES._ Bacilli are found in all the internal organs, notably in the spleen, in blood and in the enlarged glands. Body does not show much emaciation; decomposition commences early. Black hæmorrhagic patches are often found on the skin. The brain and membranes are congested. Sanguinous or serous effusions are found in serous cavities. Right side of the heart is dilated and is usually found full of coagulated or liquid blood. Cardiac muscles pale. The liver is enlarged and congested. The spleen is much enlarged, soft and congested. Hæmorrhagic patches have been found in the stomach. The mesenteric glands are enlarged. Kidneys congested. Bladder is sometimes found filled with bloody urine. The buboes are sometimes found to be soft and caseous. The tissues surrounding them are infiltrated with a reddish gelatinous exudation. The whole lymphatic chain from groin to the glands of the sacral or lumbar plexus, or from the axilla and neck to the glands of the mediastinum are affected. The internal glands are found more or less enlarged, injected and infiltrated with sanguineous fluid. The lymphatic follicles and Peyer’s patches in the intestines are found swollen. Hæmorrhages are found in the mesentery. _PREVENTION._—