262 BAGTERIOLOGT. 



lumps of mealy-looking granules. They are never 

 moist, and frequently have the appearance of coarse 

 meal which has been spread upon the surface of the 

 medium. In the lower part of the tube in which they 

 are growing, i. e., that part occupied by a few drops of 

 fluid which has in part been squeezed from the medium 

 during the process of solidification, and is in part water 

 of condensation, the colonies may* be seen to float as a 

 thin pellicle upon the surface of the fluid. 



The individuals making up the growth adhere so 

 tenaciously together that it is with the greatest difficulty 

 that they can be completely separated. In even the 

 oldest and dryest cultures pulverization is impossible. 

 The masses can only be separated and broken up by 

 grinding in a mortar with the addition of some foreign 

 substance, such .as very fine, sterilized sand, dust, etc. 



The cultures are of a dirty-drab or brownish-gray 

 color when seen on serum or on glycerin-agar-agar. 



On potato they grow in practically the same way, 

 though the development is much more limited. They 

 are here of nearly the same color as the potato on which 

 they are growing. 



On milk-agar-agar they are of so nearly the same 

 color as the medium that, unless they are growing as the 

 mealy-looking masses considerably elevated above the 

 surface, their presence is less conspicuous than when on 

 the other media. 



In bouillon they grow as a thin pellicle on the sur- 

 face. This may fall to the bottom of the fluid and con- 

 tinue to develop, its place on the surface being taken 

 by a second pellicle. 



Under all conditions of artificial development the 

 cultures of this organism are always very dry and 



