In addition to these cases, productive inflammatory changes were discovered five times affecting vessels in or near frank inflammatory processes. The animals affected with this productive process were three birds, a rodent and an elephant. In the case of two birds and the rodent the process was associated with chronic intestinal lesions, while in the elephant it was found as an endarteritis obliterans in large vessels of the lung of chronic pulmonary tuberculosis occurring in this animal. These instances serve as examples of the truly productive inflammatory processes affecting vessels and illustrate the distribution through the animal kingdom. Pathogenetically there are no essential differences, and histologically they correspond to the forms seen in man. Had every piece of tissue been subjected to microscopy wherein such lesions might have existed, more examples might have been discovered, but these processes excite no peculiar secondary effects so that attention is not drawn to them directly. The only noteworthy difference between mammals and birds is the fragile character of the clots in the latter class. This is peculiar because the principal response of this class to an infectious irritant is coagulation necrosis, liquefying enzymes apparently being absent or small in quantity. Fatty deposits in the aortic intima are by no means uncommon in the human subject and are encountered at all ages, even in youth at a time when progressive arteriosclerosis does not accompany them. There is a belief in many quarters that this fat may be laid down and then removed. Such deposits are exceedingly rare in wild animals; when they occur it is in small indefinite patches and not the bands or rows as found in man. TABLE 5. _Table Showing the Incidence of Degenerative Arterial Disease, the Percentage in Animals Subjected to Autopsy and the Principal Associated Pathology._