rort] LIPMAN—SOIL BACTERIA ges 
fication.” It is needless to say that these terms are not only too 
long, but when taken together with ‘‘Nitratreduktion” and 
““Salpeterassimilation,”’ as employed by LOunts,° they are far from 
removing the existing confusion. 
In the same way the terminology relating to the formation of 
nitrogen compounds by microorganisms out of elementary nitrogen 
is not at all satisfactory. The terms “Stickstofffixierung,”’ “Stick- 
stoffsammlung,” and ‘‘Stickstoffassimilation”’ are used interchange- 
ably in the German publications. The English terminology, with 
its “‘nitrogen-fixing,” “‘nitrogen-gathering,”’ and “‘nitrogen-assimi- 
lating” bacteria, is as unwieldy as the German “Stickstofffixierende 
Bakterien,” or the French ‘microbes fixateurs d’azote.’’ To 
make matters worse, there has crept into American publications’ 
me use of “nitrification” and “nitrifying”? as synonymous with 
“nitrogen-fixation” and ‘“nitrogen-fixing,” respectively. 
Almost as much confusion exists in the designation of other 
physiological reactions. One is uncertain in these days whether 
“methane bacteria” are organisms capable of decomposing cellulose 
with the formation of methane, or are merely organisms capable 
of oxidizing methane to water and carbon dioxide. It is difficult 
to decide, at times, whether the term ‘‘sulphur bacteria” refers to 
the organisms capable of oxidizing hydrogen sulphide partly, or 
to those capable of oxidizing it completely. Other examples of 
indefiniteness or confusion may be found in the terminology of 
sulphate reduction, hydrogen formation and oxidation, andammonia 
Production and transformation. 
The foregoing examples will suffice to show that there is need 
for more rigid definition and classification in the domain of soil 
bacteriology. Indeed, this need is so pronounced that the writer 
has been led to prepare the present paper in spite of his desire not 
to introduce striking innovations, and in spite of the knowledge 
that any proposed change in the terminology already existing will 
be criticized. The writer would add here, however, that it is not 
his intention to propose any change either morphological or physio- 
logical in’ the general classification of bacteria. It is his wish, 
* Op. cit., pp. 477-478. 
’ See FLetcuer, “Soils.” 
