274 



Profs. Percy Frankland and Marshall Ward. 



Series D. 



This series of experiments was designed to seek answers to the 

 following questions: — 1. Can an anthrax known to he incapable of 

 developing spores (asporogenous) maintain itself in the Thames water 

 side by side with other organisms, or in the same deprived of the 

 water forms by filtering through porcelain ?* 2. Is there any 

 appreciable difference in behaviour between the asporogenous anthrax 

 and a virulent race known to be capable of developing spores ? 



As matters turned out, we had to abandon the series in the middle, 

 owing to the discovery that our so-called " asporogene " was a very 

 much enfeebled form, but not utterly devoid of the sporogenous 

 power, f and partly owing to a mishap with the filtered series. We 

 select some of the results — see Tables D (I) to D (III) — because the 

 approximate numbers obtained are useful ; but we are engaged in 

 repeating the series with a more reliable culture of the "asporogenous 

 anthrax." 



The arrangement of the flasks, &c, was much as before. Four flasks 

 were filled with the crude Thames water, not infected, and examined 

 daily. Four flasks were filled with the same collection of water, 

 and to these anthrax was added as follows : — Two received virulent 

 anthrax liquid in the proportion of 1 c.c. to every 25 c.c. of water ; 

 and two received the same proportion of liquid through which 

 " asporogene " anthrax was distributed. 



Finally four similar flasks were filled with the water (same batch), 

 filtered forthwith through a Chamberland porcelain filter, and infected 

 exactly as the last. The virulent anthrax came from an agar cul- 

 ture, growing well at 30° C. for 24 hours, and in excellent condition. 

 The " asporogene " anthrax was also growing vigorously on agar 

 under the same conditions. In each case the infecting liquid was 

 made by evenly distributing quantities of the anthrax, as equal as 

 possible in quantity and as free from agar as we could remove it from 

 the tubes, in sterile distilled water. It will be noticed that all the 

 plates were made with a dilution of 20 times as much water as corre- 

 sponded to the original infected liquid. As before, the plates were 

 made daily for a week, and the numbers given in the columns 

 depend on several countings. 



# We decided not to use the water sterilised by heat in this series, in order to 

 reduce the number of flasks and plates which it would entail. 



f The asporogenous anthrax employed was not the spontaneous natural form, 

 but one produced artificially by degeneration with carbolic acid. 



