On November 27, 1912, a sick cat was brought to the laboratory for examination. It was reported that the animal was found in a warehouse in which dead rats had been found some time previously. The rats were not examined. In the morning of the 30th, the cat was found dead in the cage where it had been kept under observation. The following are the post-mortem findings: The animal was a fairly well-nourished female.[16] The subcutaneous tissue, pericardium, mediastinum, and mesenterium contained considerable amounts of fat. [16] The cat was the mother of 4 kittens which were about 3 weeks old at the time the cat was delivered for examination. They were kept under observation for several weeks, but showed no signs of plague infection. The subcutaneous tissue of the neck showed œdema and small hemorrhages. The submaxillary tissues were swollen on both sides. When the fasciæ and superficial muscles of the neck were removed, enlarged glands were found on both sides. These were closely attached to the submaxillary salivary glands. The surrounding tissue was œdematous, but no hemorrhages were noticed in the vicinity of the enlarged glands. Upon section the glands were found to be necrotic, and upon pressure a thin purulent liquid escaped. There were no hemorrhages within the glands. Several enlarged lymph-nodes, smaller in size, could be followed down the neck on the left side. The lymph-nodes in the axillæ as well as in the groins and peribronchial nodes were normal. The mesenteric glands were slightly enlarged and reddened. The lungs were slightly collapsed. A clear, sanguineous, slightly coagulated effusion was observed in both pleural cavities. The tissue of the lungs showed considerable œdema and hypostasis. The bronchi and pharynx showed no changes, the mucous membrane being pale and thin. The heart was normal. The spleen was enlarged, of light red color, with follicles slightly prominent. The stomach contents was blackish in color; there were no hemorrhages or ulcers in the mucosa. The liver was somewhat enlarged. The organ showed prominent structure, the centres of the acini being red, the periphery lighter in color. The kidneys were slightly enlarged and pale. The capsule peeled off easily, the venæ stellatæ were prominent, the surface smooth; there were no hemorrhages. The cortex was increased in breadth and was of the same color as the surface; the pyramids were darker in color. The organ was of fragile consistence. Suprarenals were normal, as were also intestine and bladder. The histological findings were as follows: _Bubo._--The capsule of the gland was œdematous. The whole gland as seen in cross section had undergone necrosis, except a few foci which still showed cellular structure.