226 BACTERIOLOGY 



track. On agar, a stripe-like grey deposit develops rapidly 

 at 35 C. 



Diplococcus albicans tardus. Unna and Tommasoli found 

 this microbe in cases of eczema. The diplococci are im- 

 motile, sometimes arranged in clumps and chains, and do 

 not liquefy gelatine. Eoundish colonies form on plate - 

 cultures, presenting an uneven lumpy surface when 

 examined under the microscope. The colonies gradually 

 become greyish-yellow, lighter in the centre and at the 

 margin, so that they appear girdled by a light zone. 

 Thrust-cultures show a superficial yellow coating, surface- 

 cultures on agar a greyish -yellow stripe with uneven edges. 



Diplococcus citreus liquefaciens. In cases of eczema Unna 

 and Tommasoli also found immotile cocci which liquefy 

 gelatine by their growth. Whitish dots develop on the 

 plate, which rapidly become fluid and assume a lemon - 

 yellow colour. Thrust-cultures show a yellowish coating 

 at first, but after a few weeks a portion of the lemon - 

 yellow culture is seen floating in the liquefied mass, while 

 the rest, which has also a yellow tint, is found at the 

 bottom. The lemon-yellow colour on the surface of the 

 fluid mass is particularly characteristic. A yellowish layer 

 forms upon agar, and also on potato. 



Diplococcus flavus liquefaciens tardus. Besides the micro- 

 organisms just described, the same observers found in cases 

 of eczema diplococci shaped like a roll of bread, which liquefy 

 the gelatine rather slowly. Punctiform brownish-yellow 

 colonies form on the plates, and yellowish masses float on 

 the surface of the gelatine when it has become fluid. In 

 thrust-cultures also liquefaction progresses, but with such 

 extreme slowness that two months elapse before half a 

 cubic centimeter of gelatine is liquefied. A thick slimy 

 coat of greenish-yellow colour develops on agar, and a 

 lumpy sulphur -yellow deposit upon potato. 



