A review of our records shows that among 5365 animal autopsies we have recorded anemia of probable secondary character in 122 instances, 53 (2.8 per cent.) mammals and 69 (1.9 per cent.) birds. The orders represented, with the percentage for the order, are Primates, 25 or 5 per cent.; Carnivora, 18 or 3.7 per cent.; Ungulata, 3 or .8 per cent.; Marsupialia, 4 or 2.2 per cent.; Rodentia, 3 or 1.5 per cent.; Passeres, 37 or 2.7 per cent.; Psittaci, 9 or 1.3 per cent.; Herodiones, 8 or 8. per cent.; Columbæ, 7 or 4.7 per cent.; Picariæ, 2 or 2.3 per cent.; Striges, Galli, Gaviæ and Accipitres, each one case. A consideration of their associated pathology reveals the fact that four changes are prominently associated with secondary anemia, to wit: gastrointestinal inflammation, 26 times (15 mammals and 11 birds); parasitism, 29 times (7 mammals and 22 birds); osteomalacia, 24 times (18 mammals and 6 birds), and nephritis, 18 times (12 mammals and 6 birds); a few of these cases overlap, but this is rather the exception than the rule, and this does not militate against the importance of the connection with anemia. It will be noted that practically all the important orders of animals are represented, including species from all over the globe. There is, however, no especial relation of anemia to the kind of diet or digestive tract. Conclusions as to the meaning of these figures of incidence are hardly justifiable. In so far as the blood picture is concerned we can only record the qualitative appearance and the effect upon tissues. It cannot be stated that to external observation a secondary anemia presents any distinguishing features that a specimen in poor condition may not exhibit. The monkeys formerly dying of tuberculosis had not infrequently pale buccal mucosa and skin around the eyes, but upon examination of their viscera, blood or marrow the quality of their blood could not be called greatly substandard. Slide smears of secondary anemia in many specimens would occasionally show stippling or a moderate number of nucleated cells with anisocytosis and poikilocytosis. This is much more frankly exhibited in the Aves, wherein displaced karyolytic or pyknotic nuclei are very common. Mention has been made of the rifts in the protoplasm, seen in Herodiones, and this has been observed in other orders. Perhaps the most striking change is the increase of young erythrocytes and of thrombocytes in the winged creatures. The nucleus of the former reminds one of that of the human plasma cell.