tion of which roots are capable. The existence of 

 anaerobic bacteria is common knowledge and it is 

 even more significant for the present problem that 

 many organisms ate able to live either aerobically 

 or anaerobically, suiting their metobolism to the 



1. The classical investigations are 

 those of Paster on the butyric bacteria, C. R. 52 ; 

 344-347 (1851). ITor summaries of more recent work 

 see Chudiakow,- Kochs Jahresber. 1897 ; 44, Gentbl. 

 Bakt., Abt. II, 4: 389 (1898); Porodko,- Jahrb. wiss. 

 Bot. 41: (1904); Lesser,- Ergeb. Physiol. 8_: 

 742-796 (1909); Larshall,- Uicrohiology, 2nd ed. pp. 



(191G). On anaerobic worms see Bunge,- 

 Zeits. physiol. Ghem. ,8: 48 (1883), 12: 565 (1888); 

 V/einland,- Zeits. Biol. 42: 55-90 (1901), 43: 86-111 

 (ly02), 45: 113-116 (1904), 45: 517-531 (1904), 48: 

 87-143 (1906). On anaerobic protozoa see Putter, - 

 Zeits. allg. Physiol. 5: 566 (1905). 



