86 THE ROYAL SOCIETY OF CANADA 



white. There were, it is true, variations in the extent of growth. 

 Thus while the growth of 6087 was abundant, it was more delicate 

 than was the case with all the other strains. All were Gram positive, 

 though here again there was variation — in some all the individual 

 bacilli were Gram positive (107, 316, Falfurias, Davis, 6087, Burt, 

 Borden mule, Boerner, and the three stock cultures) while the remain- 

 ing three (108, 109, 6071) showed some Gram negative interspersed 

 among the Gram positive bacilli. Many of the strains showed beading; 

 but our experience is that this is a variable property: successive 

 growths taken from the same stock culture will exhibit now beading, 

 now absence of beading. There was variation also in the shape, namely 

 most strains exhibited the typical square ends; but certain strains 

 (109, Davis) presented club and dumb-bell forms, and 108 and Davis 

 possessed rounded ends. 



Here again our experience is that prolonged growth in the labora- 

 tory media leads to variation in size and shape. Regarding spore 

 formation, all presented central spores. There was, however, some 

 variation in the rapidity and extent of production. A more striking 

 variation was observed in the viscosity of the different strains. Some, 

 (107, O.S.C.i, 0.S.C.2, and H.L.) were drier and somewhat granular, 

 easily breaking apart or flaking on attempted removal : the majority 

 were distinctly shiny, stringy on attempted removal. These more 

 shiny produced the more perfect emulsion in salt solution, whereas 

 the granular forms tended to remain adherent, forming a sediment in 

 the salt solutions. These four forms, therefore, required care in the 

 process of planting from the salt solution on to the agar slants and in 

 them it was found advisable to transfer some of the sediment. 



The method of testing followed closely that described in the pre- 

 vious paper submitted by one of us. All cultures were transferred to 

 plain agar slants, left to grow for five days, then examined for spore 

 formation. All showed this. Saline solution was heated in the water- 

 bath, which has already been described, to 80°, 85°, 90°C. Spores 

 were then transferred by means of a platinum loop from the agar cul- 

 tures to tubes containing the heated saline solution, maintained in the 

 bath at a constant temperature for one hour, and then replanted upon 

 agar slants. If no growth was observed after an incubation period 

 of forty-eight hours, the results were regarded as negative. The 

 results are given in Table I. All were capable of growth after heating 

 at 80 °C, none after heating at 90°, while five of the fourteen resisted an 

 exposure to 85 °C. 



