In the human being, the carnivore and the ruminant, the ileum presents the most definite picture of enteritis. In the bird, the duodenum shows the prominent lesions, and with the exception of specific diseases like blackhead, is always involved when the smaller coil of small intestine is affected. This is true whether the enteritis be nonspecific or be associated with cholera of chickens, ducks or parrots. The colon presents peculiar lesions in but few birds. Ulcerative and necrotizing processes have been encountered in three orders, Psittaci, Anseres and Herodiones, suggestively like the specific forms seen in the ceca. Microscopy and one unsuccessful culture failed to reveal a mould or protozoön. The condition appears as a gray white plaque in the cloacal wall or it may spread up to the colon and around the urethral orifices. At times it is superficial upon the mucosa and may be covered by a pseudomembrane. The chief interest in the ceca centres about enterohepatitis either of heterakis and amœbic origin or that supposed to be due to coccidia or Bac. scoticus. This specific form has been encountered only in Galli (three of the four families). It has been so well described by Hadley, Smith, Morse and Cushman that it is unnecessary to discuss it since we have nothing to add to its pathogenesis or pathology. At a later time some attention will be given to our experience with Quail disease. What is more interesting from a comparative standpoint, besides having a bearing upon blackhead, is the discovery of heterakis in the ceca, and hemorrhage and fatty change in the liver without amœbæ or coccidia in either place (unfortunately no bacteriology was done), in a Sebastopol Goose (_Anser domesticus_), a bird which has ceca not unlike the gallinaceous varieties. This is a single observation and must be treated expectantly. Microscopically the avian digestive tract in its various inflammatory states presents a few noteworthy features. The primary reaction, sometimes the only one, to irritation is injection of the vessels in the villi or deeper mucosa. To this, however, is nearly always added a granularity of the epithelium, without much evident mucus (goblet cell) formation. When the epithelial degeneration is marked there appears a round cell increase in the deep mucosa shortly followed by a similar infiltration into the villi. True catarrhal enteritis as described for the cats is not as common as some combination of the changes just detailed, but when it occurs is best developed in the carnivorous avian tract. The most striking cellular finding is the round cell of the infiltrate. It is of the middle lymphoid size with clear protoplasm, or, when late in the disease, may be small and so-called adult. Polynuclears, unless eosinophilic, and endothelioid cells are rare.