502 TH. THJ0TTA AND ODD KINCK EIDE 



strain of bacilli was quite typical until the month of May, when we 

 observed that a new type of colonies became dominant in the cultures. 

 The main characters in which these differed from the ordinary colonies 

 were their large size, their shiny, wet aspect and their lack of agglu- 

 tinability. The new type was present in great numbers while the ordi- 

 nary type was markedly reduced. The condition became quite stabile 

 and was the same all the summer and autumn, when the patient passed 

 out of our observation. 



The strain studied by us was isolated from the urine in Sep- 

 tember, 1919, and has now (March, 1920) the same characters 

 as it had immediately after isolation from the patient. 



On the surface of litmus agar it forms large, wet, shiny colonies 

 that are much elevated over the surface and have a regularly 

 rounded circumference and top. If growing very close together 

 they flow into each other, forming large irregularly shaped fig- 

 ures, that may be taken to be isolated colonies of a peculiar 

 aspect, but in reality are formed from several colonies melted 

 together. These appearances have led Fletcher to talk about 

 colonies of ameboid shape, an expression that is certainly justi- 

 fied, if it is remembered that these figures are not isolated col- 

 onies. Viewed by transmitted light the colonies have a very 

 dense mass that has a distinct reddish hue. Left outside the 

 incubator for some days the colonies, sometimes, dry up, and sink 

 together and the color deepens into a clear blue. In this stage 

 they look more like true paratyphoid than in a fresh condition, 

 when their appearance is distinctly against this diagnosis. 



Cultivated in carbohydrates the atypical strain ferments the 

 sugars just as a paratyphoidbacillus should do, and it does not 

 form indol in broth. Examined under the microscope in living 

 condition, the bacilli of the atypical strain are as a rule quite 

 immobile. Here and there is seen a bacillus showing slight move- 

 ment, in no respect like the common vivid motions of the para- 

 typhoidbacilli. In fixed and dyed films the bacilli are exceed- 

 ingly small, often being chained together like diplobacilli or even 

 like diplococci. 



Testing the agglutinability of these bacilli, we found that they 

 completely lacked the ability to be agglutinated in the prelimi- 



