48 A BARE BACILLUS. 



The bacillus has survived many names, and appears as 

 you see from time to time without apparent cause, and has 

 hitherto been apt to outstay its welcome, and to produce 

 commotion and discomfort everywhere. 



Specimens of the bacillus were exhibited at Oxford a 

 year or so ago, and aroused much interest ; the only times I 

 have seen it here are the early autumn of 1897 and again 

 last month. It is fickle and uncertain in its growth, and 

 though specimens have been known to retain their vitality 

 after being enclosed in a hermetically sealed tube for upwards 

 of 18 months, it does not always respond to attempts to culti- 

 vate it when wanted for exhibition purposes. During the 

 last 48 hours some I have has started into fresh activity under 

 the influence of heat and moisture in an incubator kept in the 

 dark, and I hope at some future meeting to be able to show 

 those who care to see it a quantity of the bacillus with the 

 most roseate hues. 



One other peculiarity of the bacillus prodigiosus may be 

 of interest, viz., the antagonism it appears to have for some 

 others of more or less the same kind. 



When several organisms are associated in a liquid culture 

 one species may take precedence, and others develop later, or 

 two or more species may develop at the same time, or the 

 growth of one species may prevent the growth of another by 

 either exhausting the food material by its rapid growth, or by 

 producing products which retard or destroy the other. Thus 

 it is said by some observers that our bacillus prodigiosus is 

 antagonistic to several others, and I think this is probably 

 due to the tri-methylamine or the lactic acid it gives rise to. 



Serum therapy depends on this antagonism or symbiosis 

 as it is called, hence the use of anti-diphtheritic and other 

 serums, but on the other hand the presence of one bacillus 

 sometimes increases the activity of another, and attenuated 

 cultures of anthrax bacilli may re-acquire virulence if injected 

 simultaneously with a culture of bacillus prodigiosus. 



Amidst the " wars and rumours of wars " now agitating 

 civilisation, it is well that the nature of the bacilli is so much 

 better understood, and I think it no less fortunate that in the 

 simple and harmless Formalin we have now a means of exter- 

 minating one of the most remarkable species of that wonderful 

 family. 



