272 Profs. Percy Frankland and Marshall Ward. 



Here we see, on examining Table C (I), in spite of unavoidable 

 imperfections in the observations, due to the difficulties of counting 

 and of observing when liquefaction commences, that both the 

 anthrax and the water organisms may run a similar course as regards 

 the first few days ; in both cases the climax is rapidly reached (about 

 the third day) and then a decline sets in. But it is worth notice 

 that even after seven days' standing the anthrax is not eliminated, 

 and we were so struck with the importance of this phenomenon 

 that I decided to employ further tests to see if this persistence 

 was really due to the continued vegetation of the anthrax or to 

 the development of spores. 



I was driven to suspect spores by several facts. In the first place 

 Strauss and Dubarry have shown* that anthrax can form spores 

 after being placed in water, provided the temperature is not too low 

 (20° C.) ; secondly, we noted in some plates that the anthrax colo- 

 nies were hanging back, so to speak, in their development, and it 

 seemed not unlikely that this was due to time being needed for 

 the germination of spores. 



To test this point we placed a few cubic centimetres from one 

 of the flasks of this group on April 7, i.e., eight days after the last 

 culture, for 24 hours at 60° C, and, before heating the liquid, 

 inoculated a guinea-pig and a mouse with a trace of it. 



Both guinea-pig and mouse were dead on April 9, i.e., after 48 

 hours, and that their death was due to anthrax was proved by find- 

 ing the bacilli in the blood of the heart, and by obtaining pure 

 cultures therefrom. 



The water heated to 60° C. for 24 hours gave pure cultures of 

 anthrax also, showing conclusively that spores had been formed in 

 the water. These cultures also justify the conclusion that aquatic 

 normal forms did not develop spores, unless we assume that their 

 spores are less resistent to moderately high temperatures. With- 

 out laying too much stress on the numbers, therefore, I think 

 Table C (I) shows that while Bacillus anthracis can only live vege- 

 tatively and maintain its hold for about three days in the crude 

 Thames water at 20° C, it can form spores there which enable it to 

 live for a longer period, f and I conclude not that the competing 

 water forms destroy the bacilli, but that the decrease of anthrax on the 

 plates is due partly to its passing into the spore condition, and to the 



* See our First Report, p. 268. 



f "We shall show later on that these spores can remain alive for several months, 

 a result well established by previous observers. Duclaux, for instance, found that 

 there were spores still alive in some of Pasteur's old flasks which had been kept 

 for twenty-one or twenty-two years, and showed that in those flasks where they had 

 died it was probably owing to the acid or alkaline reaction of the media. (See 

 De Bary, 'Lectures on Bacteria,' 1887, p. 54.) 



