82 THE ORIGIN AND EVOLUTION OF LIFE 



before the first chlorophyllic stage (Algas) of the evolution of 

 plant life. Among such bacteria, possibly surviving from 

 Archaeozoic time, is one of these "primitive feeders," namely, 

 the Nitroso monas of Europe.^ For combustion it takes in 

 oxygen directly through the intermediate action of iron, phos- 

 phorus, or manganese, each of the single cells being a powerful 

 little chemical laboratory which contains oxidizing catalyzers, 

 the activity of which is accelerated by the presence of iron and 

 of manganese. Still in the primordial stage, Nitroso monas 

 lives on ammonium sulphate, taking its energy (food) from 

 the nitrogen of ammonium and forming nitrites. Living sym- 

 biotically with it is Nitrobacter, which takes its energy (food) 

 from the nitrites formed by Nitroso monas, oxidizing them 

 into nitrates. Thus these two species illustrate in its simplest 

 form our law of the interaction of an organism {Nitrobacter) with 

 its life environment {Nitroso monas). - 



These organisms are wide-spread: Nitroso monas is found 

 in Europe, Asia, and Africa, while Nitrobacter appears to be 

 almost universally distributed. 



These "primitive feeders" are classed among the nitrifying 

 bacteria because they take up the nitrogen of ammonia com- 

 pounds. Heraeus and Hlippe (1887) were the first to observe 

 these nitrifiers in action in the soils and to prove that pre- 

 chlorophyllic organisms were capable of development, with 

 ammonium and carbon dioxide as their only sources of energy. 

 Nine chemical "life elements" are involved in the life reac- 

 tions of these organisms, namely, sodium, potassium, phos- 

 phorus, magnesium, sulphur, calcium, chlorine, nitrogen, and 

 carbon. This discovery was confirmed by Winogradsky (1890, 

 1895), who showed that the above two symbiotic groups ex- 

 isted; one the nitrite formers, Nitroso monas, and the other the 



1 Fischer, Alfred, 1900, pp. 51, 104. ^ Jordan, Edwin O., 1908, pp. 492-497. 



