BY R. GREIG SMITH. 657 



are firm and adhesive; the larger are watery- The gelatine is not 

 liquefied. 



Frank,* under the name Hhizohium hguminosarum, descril)esi 

 an organism which seems to he Beijerinck's bacterium. The 

 rhizobia are actively motile, rounded to long in shape, and 09 to 

 1-3 /x in length. There are also non-motile forms; flagella, how- 

 ever, could not be found. Curved forms, more or less constricted 

 in the middle, apparently a division stage, were frequently 

 observed. Zooglcea forms also wei-e seen, and these often con- 

 tained in the gelatinous matrix very short coccus-like bodies, the 

 size of which was estimated at 02 /x. Spores were not observed. 

 On gelatine the colonies grow slowly, reaching a diameter of 

 1 mm. in about a week. They are small, rounded to elliptical, 

 raised, of a pale yellow colour and mucilaginous. The gelatine is^ 

 sometimes liquefied. 



Kirchnerf claims the organism of the 8oja Bean as a variety 

 of Rhizohium. The rods are generally somewhat bent, and 

 measure 0-8 : 3 -2-3 -6 /x. They show a granular content when 

 stained, and are non-motile. On gelatine the colonies grow 

 slowh', forming raised, rounded, transparent, white paraffin-like 

 drops which do not liquefy the medium. Laurent,; in discussing 

 the organism of the nodule, prefers the designation Rhizohium 

 legiiminosarum, liut he diff'ers from Frank in respect to its 

 morphological characters. The colonies on gelatine are whitish, 

 and have a glistening surface. The strongly developed colonies 

 are slimy, the slime staining well with dahlia violet, yellow with 

 iodine, and shows no cellulose reaction. It thrives well in media 

 destitute of nitrogen. Sugar, especially saccharose, is favourable. 

 When the medium is 5 mm. deep, a slimy precipitate is formed; 

 when 1 cm. deep fioccules are oV)tained, and with deeper layers 

 there is only a turbidity. The medium should be neutral or 

 slightly alkaline. 



* Frank, Centralhlatt fur Bakt. 1 Abt. ix. 629. 

 t Kirchner, ihid., 2 Abt. ii. 96. 

 :;; Laurent, ihid.. 1 Abt. ix. 703. 



