141 



distinct in the photographs as could be wished, namely the 

 „granulations". By these are meant sharp but irregularly defi- 

 ned formations which are seen in most of the Pfeiffer's bacil- 

 lus colonies best with a magnification of 100, when they have 

 reached a sufficiently developed state. The schematic figures 

 „Sch ernes of colonies" in plate 3 give an idea of their size 

 and arrangement. 



„I 1" spreads, from a dark centre, well on all sides and at- 

 tains a diameter of 5y 2 mm. The edge is quite flat, very undula- 

 ting and jagged, and the surface is rough in the peripheral portions. 

 In the centre there are but few granulations. 



The investigations „I" and „II" showed precisely the same form 

 of growth. In „I" it was noted that after l3/ 4 days there were just 

 a few scattered granulations in the centre; after another day in the 

 incubator numerous well-distributed granulations were present. This 

 is the strain that shows most markedly and constantly the fringe 

 formation referred to above even around a culture produced by a 

 heavy inoculation (compare plate 1). 



„I 5" is considerably smaller but must be counted as a large Pfeif- 

 fer's bacillus colony. Its shape is totally different from that of 

 „I 1", as it declines at first slightly and then with an increasing 

 gradient from a sharply defined central plateau. The edge is only 

 slightly undulating. The colonies "are rather dark. There are a 

 few central granulations. 



In the investigations „I" and „II" the colonies were also large 

 and had a slight tendency to granulation formation. In ,,I" it was 

 noted that ,,the colonies are considerably lighter than I 1. Numerous 

 line undulations in the edge were present". 



The cracks occurring in the two colonies described were pro- 

 duced in the preparation. 



„I 6" is rather smaller than „I 5". It has a similar shape but 

 the margin is narrower and flatter. The edge is smooth and cir- 

 cular. Around the centre there is a little group of granulations. 



In ,,I" and „II" the colonies were also of medium size with a 

 round border and granulations in the centre. 



,,I 21" is a rather large colony, somewhat dark, but possessing 

 a narrow light-coloured fringe with an undulating edge. The granula- 

 tions are present in scattered array, thickest around the centre. 



In „1" was noted, — rather dark, medium-sized colonies with 

 slightly undulating edge; centrally grouped granulations. In „II" 

 the colonies were comparatively clear, with very undulating edges. 

 ,,I 23" is a large dark colony with a margin divided into two 

 sections. The border is regular and circular. There are a few 

 centrally-placed granulations. 



In „I" and „II" was noted, — medium-sized dark colonies with 



