torr] LIPMAN—SOIL BACTERIA 459 
nitro. It will be remembered that nitrifying bacteria, according 
to the accepted definition, are organisms capable of changing 
ammonia into nitrites and nitrates. If it be true, as it is claimed 
by Kaserer, that there are organisms capable of oxidizing ele- 
mentary nitrogen directly to nitrates, they should be included under 
the azoto-bacteria, the true nitrogen-fixing bacteria. Hence, 
nitrification deals properly with the transformation of nitrogen 
compounds, more strictly speaking, the oxidation of combined 
nitrogen. Now, since denitrification is a reduction of combined 
nitrogen, it should not include processes where elementary nitrogen 
is formed. The latter are the opposite of azotofication (nitrogen- 
fixation), and should therefore be included under deazotofication. 
In other words, KAysEr’s and Léunts’ direct denitrification would 
become deazotofication under the proposed terminology, and their 
indirect denitrification would properly become denitrification. 
The advantages of the proposed arrange mes are so evident thet 
further discussion is hardly necessary. 
The next group of de-proteo-bacteria wert naturally include 
the organisms of decay and putrefaction, and the term employed 
here should therefore refer to dissimilation processes. It is evident 
at the same time that many de-proteo-bacteria would also be 
proteo-bacteria and vice versa. Objection may be raised for this 
teason to de-proteo, as well as to proteo; nevertheless, because of 
their supplementing the very convenient terms proteofication and 
deproteofication, they should be retaine 
The group of de-azoto-bacteria would tds all species capable 
of breaking down nitrogen compounds with the evolution of ele- 
mentary nitrogen. Starting with amino-compounds, ammonia, 
nitrates, or nitrites, we could have amino-azo-, ammono-azo-, 
nitra-azo-, and nitri-azo-bacteria. As was already indicated above, 
the direct denitrifiers would be designated here as nitri-azo- or 
nitra-azo-bacteria. Similarly, the organisms capable of oxidizing 
ammonia with the evolution of elementary nitrogen would be 
designated as ammono-azo-bacteria. 
We come finally to the sulpho-bacteria and de-sulpho-bacteria, 
Organisms concerned with the oxidation of hydrogen sulphide and 
elementary sulphur on the one hand, and of reducing sulphates 
