BACILLI 465 



BACILLUS INCANUS 



I LIQUEFIES GELATINE 



Authority.-- Pohl, ' Ueber Kultur und Eigenschaften einiger Sumpfwasser- 

 bacillen,' Centralblatt f. Bakteriologie, vol. xi., 1892, p. 192. 



Where Found. In marsh-water. 



Microscopic Appearance. Bacilli 1-7 /* long and 0-4 /x broad. Occurs 

 usually lying parallel, two to four individual bacilli side by side. It is slightly 

 motile. 



Cultures. 



GELATINE PLATES. Forms circular granular colonies with a smooth dark 

 rim. The gelatine is only slightly liquefied. 



GELATINE TUBES. Produces a grey white raised expansion on the surface, 

 and grows visibly in the depth. Slight liquefaction takes place after forty-eight 

 hours, which only progresses very slowly. 



AGAR-AGAE. Forms grey white granular growths all along the needle's path. 

 The condensed water remains clear. 



POTATOES. Produces an abundant and spreading grey thread-like growth. 



Remarks. When cultivated on gelatine tinted blue with litmus, the colour of 

 the latter remains unaltered, and thei'efore no acid is produced. 



BACILLUS IRIDESCENS 



| LIQUEFIES GELATINE | 



Authority. Tataroff, Die Dorpater Wasserbacterien, Dorpat, 1891, p. 57, 



Where Found. In Dorpat water. 



Microscopic Appearance. Bacillus varying in length from 3-5 to 5-2 ^ - 

 forms also long (8-7 to 10-5 p.] bent threads. Only capable of slight oscillatory 

 movements. Forms spores. 



Cultures. 



GELATINE PLATES. Forms irregular blue, greenish yellow iridescent colonies, 

 consisting of flakes composed of numerous tiny shining plates or scales ar- 

 ranged like slates on a roof. After a time a yellow central disc is visible, from 

 which liquefaction starts. Under a low power the depth colonies are granular, 

 shining yellow and circular discs. The surface colonies exhibit at first a pale 

 yellow shining, ill-defined disc, which later becomes broken up into isolated 

 windings, and surrounded by a radially folded outer zone, in which isolated con- 

 centric foldings also become visible. The appearance of the colony is very cha- 

 racteristic, and may be compared to the convolutions of the brain; the 

 central windings are fine and sharply defined, and shining yellow, whilst 

 towards the periphery they are coarser, not so sharply defined, and white. 



GELATINE TUBES. Forms a thread-like growth in the depth, and on the sur- 

 face a delicate shining basin, the centre of which is yellowish arid depressed, 

 whilst the outer zone is broad, irregular and iridescent. In three to four days 

 liquefaction commences in the centre, and a slimy yellow mass collects in the 

 depression. 



AGAR-AGAR AND GLYCERINE-AGAR. Forms a thick, shining, wavy, moist, 

 greenish yellow, iridescent expansion, the surface of which is pitted. Later it 

 becomes dirty yellow and opaque. It develops less well in the incubator. 



BLOOD SERUM. Forms a yellow moist shining expansion, which rapidly forms 

 a gutter, and the greater part of the serum is subsequently liquefied. It will 

 not develop in the incubator. 



POTATOES. Grows slowly at first, but later forms a raised dark honey-yellow,, 

 dry, shining, rough expansion, which afterwards becomes yellowish brown and 

 slimy. It will not develop in the incubator. 



BROTH. Renders it turbid, forming a yellow deposit. In the incubator the? 

 liquid remains clear. 



H H 



