BACTERIUM NUBILUM. 269 



Bacterium lactis saponacei. (Weigm. and Zirn.) 

 Lehm. and Neum. 



As the Bacillus lactis saponacei, Weigmann and Zirn 

 (C. B. xv, 463) have described a short rod, which in gela- 

 tin plates forms white colonies with yellow centers, which 

 later become yellow throughout, but without special 

 markings. Gradually liquefaction takes place. In the 

 gelatin stab a funnel forms, at the bottom of which lie 

 yellow flocculi. In the agar stab the luxuriant growth is 

 yellow in the center only at first, then throughout the 

 whole groYvrth. Upon potato a waxy-yellow, slimy growth. 

 Milk is not coagulated, but becomes slimy and slightly 

 tenacious. The culture has an odor like soap or lye. 

 Optimum at 10. Regarding soapy milk, the first com- 

 munication was by Herz, Ch. Zeit. Rep., 1892, page 

 34. 



Bacterium nubilum. (P. and C. Frankland. Z. H. vi, 

 p. 386.) Lehm. and Neum. 



Non-motile short rods, 1-2 // long, 0.3-0.5 v thick, staining by 

 Gram's method. The colonies on the gelatin plate present beautiful, 

 polymorphous forms. In the younger stage they are yellowish, of ir- 

 regular forms, and provided with many thick and thin lateral out- 

 growths, similar to mites in shape. The more compact nucleus at the 

 center gradually disappears, while the projections become arranged 

 more in the form of a star. Now liquefaction of the gelatin begins. 

 The periphery of the colony slowly dissolves into delicate little frag- 

 ments, and in the fluid contents of the saucer of liquefaction there 

 remains a framework of radiating threads, which later become ar- 

 ranged like the spokes of a wheel. Finally the entire colony breaks up 

 into irregular fragments. Microscopically the colony does not appear 

 unlike that of the Bac. subtilis. In the gelatin stab the growth sinks 

 in, with the form of a saucer, and then cylindric liquefaction occurs. 

 The liquefied zone is slightly cloudy. The growth upon agar is jagged, 

 undulating, fairly luxuriant; in the center, pale rose color; at the 

 edges, yellowish-brown, with a fatty luster. The water of condensa- 

 tion is clear with a yellowish-brown sediment. The growth upon po- 

 tato is at first entirely reddish-white, faintly shining to dry; later it 

 becomes intensely brownish-yellow. Milk is not coagulated, and is 

 alkaline in reaction. No gas is formed from grape-sugar. It forms 

 but little indol. Bouillon becomes cloudy. Isolated by Zimmermann 

 from water (i, p. 28). Our description is from one of Zimmermann's 

 cultures, 



