Chronic gastritis in the simple stomachs is almost exclusively in opossums harboring _Physaloptera turgida_, a worm which fastens itself more or less firmly in the mucosa and probably, with the assistance of bacteria, causes sufficient irritation to produce a hypertrophic change in the deeper layers and a destruction of the glands where it holds and a distortion of those nearby. One is reminded that Fibiger found spiroptera to be responsible for adenocarcinoma in rats; no tumor formation has been found in these animals, although one opossum with such a stomach had an adenocarcinoma mammæ. Small hemorrhagic spots may occur in the deeper layers, possibly where the worms have bitten. The rugæ are irregular or interrupted by knobs and papillæ. Group B, stomachs showing chronic change, were all kangaroos. The three cases resembled the infiltrating necrotizing lesions as discussed under ulcers (page 175). The process showed an infiltration of the subsurface tissues with a gray slough over the densest part. The mucosa as a whole was irregularly rugous and spotted with red gray areas. Altogether one gets the impression that in the simpler stomach, reactive inflammation is most prominent, while in the colonoid stomach degeneration is greater than reaction. Intestinal lesions in marsupials are not common and not peculiar except in that they carry out the pathological reaction as seen in the stomach. The carnivorous intestine shows frank catarrhal changes, the herbivorous presents congestions and superficial necroses. These two groups then follow the descriptions as already given for carnivores and ruminants. The colon presented in the first group, simple catarrhal or follicular change. In the second division the lesions resembled those in the stomach; they were only once of the three instances associated with streptothricosis. AVES. The class Aves has been treated in the chart precisely as have the mammals, but it is not possible to make the accurate diagnoses or to separate groups of lesions according to anatomy as was done for the latter class. Upon the average there is more gastroenteritis among birds than mammals, but when looking for an explanation of this, it was unfortunately necessary to enter in the “undecided” column of Table 11 a very great number of cases. This column would be greater relatively were it not for the parasites in parrots and gallinaceous birds, the entries for which are high. Besides this fact and that the owl stands at the top, the pigeons at the bottom of the list numerically, no further general statements are allowable. There are several orders with high values among those of which insufficient autopsies are at hand to cast percentages.