32 



ANAJ'JROBIC HA liJTATS 



tioii and probably in part through consumption by 

 the bacterial flora of the gastric region. Occasionally 

 larger amounts of oxygen from swallowed air seem to 

 reach the small intestine. Von Brand and Weise (1932) 

 explain in that manner the findings of Long and Fenger 

 (1917), and their own, that oxygen is present, some- 

 times in appreciable amounts, in the small intestine of 

 slaughtered pigs. 



TABLE 4 



Oxygen Content of the Fluid Intestinal Masses of Warm-blooded 



Animals. 

 Most figures represent mean values of several determinations. 



The other possibility is that oxygen may diffuse from 

 the intestinal wall into the lumen. Mclver, Redfield and 

 Benedict (1926) showed that if oxygen-free nitrogen or 

 hydrogen is introduced into an isolated loop of the 

 small intestine of a cat the gas remaining after periods 

 varying from 1 to 7^2 hours contains rather large 

 percentages of oxygen. They found 2.0 to 5.7% after 

 injection of nitrogen, and 2.9 to il5% after injection of 

 hydrogen. 



It seems somewhat difficult to reconcile the presence 

 of such large amounts of oxygen with the results of the 

 analyses of naturally formed gases as shown in Table 3. 

 One possible explanation of the difference may be that the 

 animals for which analyses of normal intestinal gases 

 have been recorded either are larger than cats or are 



