Eleven healthy and five diseased cows, most of which had been affected with traumatic pericarditis, were held on their right side, except one which was kept in the standing position, and subjected to some thoracic operation which lasted for 30 to 120 minutes. Artificial respiration with pressured oxygen was applied to them from time to time during the operation. As a result, three cows, one healthy and two diseased, died prior to the end of the operation, the remainder withstanding thoracotomy. 1. During the thoracotomy, the oxygen in the inspiration tube of the apparatus employed was 23.60 to 61.50 (39.65) per cent and the carbon dioxide in the same tube 0.04 to 1.38 (0.29) percent. 2. During the thoracotomy, the oxygen content and oxygen saturation rate of the arterial blo-
1. Gram-positive green hemolytic cocci and bacilli, Gram-positive non-hemolytic bacilli, yeast, Staphylococcus; Bacillus, and Enterobacteriaceae were isolated from nine samples of pressed ham (including two samples of sliced ham in vacuum package) and one sample of sausage, all the samples being affected with greening change. 2. Of 55 strains, consisting of 43 strains derived from the portions affected with greening change of these samples and 12 strains isolated from normal ham, all were inoculated into pressed ham and some into sausage. As a result, all the strains of Gram-positive green hemolytic cocci (4 strains) and bacilli (12 strains) and 12 of the 22 strains of Gram-positive non-hemolytic bacilli were found to have been the cause of producing greening changes in the meat products. 3. Catalase-negativity was the most characteristic biological property of those organisms causing greening change. Nevertheless, 8 of the 20 strains of catalase-negative non-hemolytic bacilli were not capable of producing greening change in any meat product. 4. Those organisms causing greening change were inoculated into meat products of different brands. As a result, products of some brands were involved in greening change, but the same products of other brands were only discolored or underwent no change. This finding suggests that greening change is produced not only by some metabolic substance of these organisms but also by some important factors on the part of the meat product (kind of meat and any substance added to the meat). 5. All the strains capable of causing greening change were not pathogenic for mice, except one strain of Gram-positive green hemolytic cocci, nor heat-resistant.