PASTEUR EFFECT 



57 



muscle (17). As end products in worm fermentation Lesser found, 

 in addition to lactic acid, large amounts of higher fatty acids, 

 especially valeric acid (cf. also 18 and 19). An increase of glycogen 

 utilization in anaerobiosis is described for many other types of 

 worms (19). The parasitic worms living in the practically oxygen- 

 free intestinal fluids show predominantly anaerobic metabolism. Al- 

 though they are able to respire aerobically, their fermentation does 

 not seem to be inhibited nor their glycogen consumption dimin- 

 ished in oxygen (19). 



The higher vertebrates and especially the warm-blooded animals 

 must be considered as essentially aerobic organisms. This is not true 

 for all their parts, however, nor under all conditions. The experiment 

 shown in Figure 2 is an example of partial anaerobiosis: the muscle 

 suddenly put under high strain must rely predominantly on a supply 

 of anaerobic energy. In Table 5 metabolic figures for representative 



Table 5.— Metabolism of animal tissues 



tissues are assembled. During recent years interesting examples of 

 adult tissues with predominantly anaerobic metabolism have been 

 described. Relatively large and aerobically persistent glycolysis has 

 been found, for example, in the medulla of the kidney and in 

 cartilage (20, 21). Dickens correlates the metabolic pattern with 

 the relatively poor blood supply of these tissues. Large and aerobi- 

 cally persistent glycolysis in the intestinal mucosa recently reported 

 by Dickens and Weil-Malherbe (22) might likewise be correlated 

 with the previously mentioned lack of oxygen in the intestinal fluid 

 surrounding it. 



These observations show that the pronounced anaerobic me- 

 tabolism of embryonic tissue and of malignant growth (Table 6) is 

 not an isolated phenomenon. Here are tissues, as has been pointed 



