444 SOIL SCIENCE 



The writer's extensive studies of the cukural characteristics of cellu- 

 lose-destroying organisms has shown that a rapid destruction of cellulose 

 occurs only when the culture medium is thoroughly aerated and contains 

 an abundant supply of available nitrogen. It is also essential that fairly 

 high temperatures be maintained. The thorough cultivation given most 

 citrus soils in southern California insures thorough aeration. The surface 

 soil to which the organic matter is usually added is generally well supplied 

 with available nitrogen. The soil temperature even during the winter 

 months is seldom below that at which a rapid multiplication of the cellu- 

 lose-dissolving organisms takes place. In view of the above stated condi- 

 tions, it would seem that the very rapid destruction of cellulose in these 

 soils is probably due more to the very favorable cultural and climatic con- 

 ditions which make possible the rapid multiplication of the cellulose-dis- 

 solving organisms in these soils. 



New Species of Cellulose-Dissolving Bacteria 

 It is obvious that an adequate knowledge of cellulose decomposition 

 in soils must be based upon a clear understanding of the character of the 

 cellulose-dissolving micro-flora of soils. This knowledge can be obtained 

 only by an arrangement of the organisms studied in a logical system of 

 classification such as will make possible a comparative study of the forms 

 described. In the establishment of the points of differentiation upon 

 which separation may be based, there are of course many possible 

 methods of procedure varying according to the points of resemblance 

 which are selected as important. 



In working out the description of new species of cellulose-dissolving 

 bacteria, an attempt has been made to bring out the individual character- 

 istics as concisely as possible. Many of the data called for by the card of 

 the Society of American Bacteriologists seem to have little significance in 

 the separation of members of this group. Moreover, in the isolation and 

 classification of this group of organisms it has been found necessary to 

 prepare several new varieties or culture media which are of especial im- 

 portance in the classification of the cellulose-dissolving organisms, but 

 would probably be of little imporance in the classification of 

 ordinary saprophytic bacteria in soils. So far as we are able 

 to determine none of the cellulose-dissolving organisms isolated 

 have been previously described as saprophytic forms. In view of 

 the above stated conditions and the fact that the power to dissolve cellu- 

 lose forms a definite basis for the group, we believe that the classification 

 of the cellulose-dissolving organisms can be most satisfactorily accom- 

 plished by the employment of only those media which are of especial im- 

 portance in differentiating the members of this particular group and by 

 using only those characters which remain constant through several sets 

 of cultures. 



