GROWTH IN TIME OF THE TOTAL ORGANISM 183 



TABLE 7 



CO2 PRODUCTION OF ArmadUUdium pdlasH (21°) 



After Miiller, 1943b 



The metabolic types mentioned are: 



1. In the first type, metabolic rate is proportional to a surface or the 2/3 power 

 of weight. Representatives of this type include fish and mammals but also certain 

 invertebrates, such as crustaceans, clams, and ascaris. Table 7 presents one 

 example, the metabolic rate in the sowbug, ArmadUUdium. As can be seen, oxygen 

 consumption per unit weight decreases with increasing body size, but remains 

 constant per unit surface. 



TABLE 8 



OXYGEN CONSUMPTION OF DixippUS mOTOSUS (20°) 



After Miiller, 1943a 



weight in mg 8 



ml Oj/h. 2.0 



per g/h. 250 



2. In the second type, metabolic rate is proportional not to surface but to weight 

 itself, so oxygen consumption in an animal of double size is doubled, in an animal 

 four times as large is quadrupled, etc. Direct proportionality of metabolic rate 

 to weight is found in growing insect larvae and hemimetabolic insects, and 

 interspecifically in the comparison of imagos of different related species. Table 8 

 shows metabolic rates in the walking stick, Dixippus morosus. Oxygen consumption 

 per gram and hour appears to be constant over a wide range, covering all body 

 sizes and the entire development. Other groups belonging to this type are land 

 snails of the family Helicidae, intraspecifically as well as interspecifically, and 

 annelids such as the earthworm. 



TABLE 9 



OXYGEN CONSUMPTION OF Plaiwrbis spec. (23°) 



After Bertalanffy and Miiller, 1943 



3. In the third type, metabolic rates are intermediate between proportionality 

 to weight and proportionality to surface. To this type belong pond snails such as 

 Planorbis and Lymnaea and flatworms like Planaria. Table 9 shows that metabolic 

 rates decrease with respect to weight, but increase with respect to surface. 



Literature p. 253 



