THE ALIMENTARY CANAL AS A SOURCE OF CONTAGION 1 5 



distance of a centimetre or so, but underneath this the culture becomes 

 more expanded and often flattened out in a single lamella whose borders 

 are occupied with a series of loop-like festoons. It liquifies the gelatine 

 in course of time, but slowly, and when liquefaction around the culture is 

 complete, the organism falls down in a greyish-coloured deposit. Gas- 

 bells may or may not be liberated ; sometimes there is a single gas-bell 

 at the deepest part. 



Like the other members of the group, the culture in glucose-beef-tea 

 bleaches dilute solutions of permanganate of potash. 



The involution forms met with, as in the case of all the members 

 of the group, are, at first, misleading. So varied may the general 

 aspect of the organism be that it might be imagined that two or 

 even three different bacteria were under observation, a fallacy which 

 must be guarded against in arriving at a diagnosis of the case. The 

 deception is particularly in evidence when Gram's process is applied to a 

 culture on glucose-beef- tea. The organism invariably gives a positive 

 reaction, but should such a culture be retained for a week or so at the 

 ordinary temperature of a sitting-room, it will be found that the Gram's 

 reaction is irregular, certain of the members giving an intense blue 

 colour, while others remain only faintly discernible, or have a distinct 

 pink tint. The pink tint is sometimes very remarkable, and forms a 

 notable contrast to the intense blue of other bacilli lying in the neigh- 

 bourhood. I have found this anomalous and irregular staining 

 reaction in several members of this group of anaerobes, and do not con- 

 sider it as peculiar to any one in particular ; not only does the colour 

 diflfer, but those which have the pinkish tint appear very much more 

 slender than those which give the ordinary deep blue colouration, so that, 

 in an unguarded moment, one is apt to suppose that they represent 

 two distinct bacilli. On examining the culture unstained, however, or 

 stained with ordinary aniline dyes, the individuals will be found to be 

 the same organism. The anomaly is evidently due to an optical effect 

 consequent upon the one being intensely coloured, the other only 

 faintly so. 



Gram's process, as the literature on the subject proves in the case of 

 Blackquarter, is extremely illusory when applied to these anaerobes, and 

 requires to be practised with the greatest care. It will sometimes happen 

 that the organism, taken from the peritoneal liquid directly, will give an 



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