INTRODUCTION 



Table 2 

 Conditions for respiration in water and air 



water through which the oxygen must diffuse, but the distances 

 are less than in aquatic forms. Ventilation, that is the pumping 

 of the medium over the respiratory epitheUum, requires the 

 animal to do work, the amount of which is far greater in water 

 than in air because of the higher density and greater viscosity. 

 The liberation of energy for this work uses oxygen and in man it 

 has been estimated that between 1 and 2 % of the oxygen uptake 



