RESPIRATION 239 



however, bean seedlings and other plants emit the same or 

 a greater volume of carbon dioxide when placed in an atmo- 

 sphere free from oxygen, as they do when growing normally in 

 the air. 



During intramolecular respiration carbohydrates and fats 

 disappear from the tissues of the plants just as in ordinary 

 respiration in the presence of abundance of oxygen, but the 

 production of carbon dioxide is accompanied by the formation 

 of alcohol and other compounds. The alcohol produced during 

 the intramolecular respiration of ripe cherries amounted in 

 one of Brefeld's experiments, to more than two per cent., and 

 in pea seedlings to over five per cent of their fresh weight. 



While the higher plants are unable to maintain their vitality 

 in the absence of free oxygen for more than a short time, 

 many of the lower forms of plant hfe, such as yeasts and 

 bacteria, are independent of the presence of free oxygen and 

 continue to live and multiply without it (p. 772). 



