CHAPTER VIII 



THE POSSIBLE OCCUBEENCE OF TRANSMUTATION 

 IN THE LIVING BODY 



The significance of the variations recorded in the foregoing 

 sections, with reference to the question whether actual trans- 

 mutation of bacteria can be brought about artificially or not, 

 will be dealt with later. It is proposed, at this point, to consider 

 another aspect of the problem, namely the possibility of 

 transmutation occurring in the tissues of the living body. 



In certain regions of the body one finds growing side by 

 side two strains of organisms clpsely resembling each other 

 in every respect save one — namely their pathogenicity. One 

 strain is capable of causing a definite train of lesions and 

 symptoms ; the other, as a rule, does not give rise to any signs 

 of disease. The suggestion that one strain may be in some way 

 a derivative of the other offers a tempting hypothesis to explain 

 both their resemblance and their proximity to each other. 

 An illustration will, perhaps, make this clearer. In the hides 

 of cattle may sometimes be found non-virulent bacilli closely 

 resembling B. anthracis. Such an organism was discovered 

 by Andrewes and described by Bainbridge (1903) under the 

 name B. cmthracoides {vide p. 92). The organism was 

 stated to differ from B. anthracis in the appearance of its 

 colonies, in its rate of growth, in possessing slight motility and 

 in being non- virulent. By slightly modifying the conditions of 

 growth, colonies on agar could be made to assume the typical 

 appearance of anthrax colonies, while its virulence proved 

 capable of increase by "passage." The differences in character 

 between this organism and B. anthracis were deemed sufficient 

 by these observers to justify them in classifying it as a distinct 

 species, but it is difficult to resist the conclusion either that 



