CH. IX] OF TRANSMUTATION 123 



phx>sus that the latter organism was soon " swamped," as it 

 were, and disappeared altogether. If the strain of B. typhosus 

 injected contained one or two specimens of a streptococcus or 

 coliform organism, might not growth in the peritoneal cavity 

 yield a similar result? — not before, however, some of the ty- 

 phoid bacilli had succeeded in escaping from the peritoneum 

 into the blood vessels and setting up a systemic infection. In 

 two instances, in which the experiments were repeated, the 

 injection of the original culture of B. typikom^ into the peri- 

 toneal cavity did not kill the animal although a pure culture 

 of B. typhosus was recovered from it. The original culture, 

 therefore, apparently contained strains differing from each 

 other in virulence. They may conceivably have possessed 

 other differences. 



(2) No control experiments were carried out to prove that 

 the peritoneal cavity before the experiment was sterile. 

 Dudgeon (1908) states that in healthy animals the omentum 

 may normally contain the staphylococcus albus. There is 

 evidence to show that even in healthy animals the internal 

 organs may contain both pathogenic and non-pathogenic 

 bacteria. Ford (1900) showed by experiments, in which rigid 

 precautions against contamination were adopted, that the 

 kidneys, liver and spleen of healthy animals, in a large majority 

 of cases, contained organisms such as the staphylococcus, 

 mesentericus, colon and paracolon bacilli, B. suhtilis and 

 protem. In rabbits 66 per cent, of the organs examined 

 contained bacteria, in cats over 77 per cent., in dogs over 88 

 per cent. In guineapigs the percentage was 77 per cent, of 

 the organs examined and the organisms that predominated 

 were B. subtilis, staphylococci and the colon bacillus. Adami, 

 Abbott and Nicholson (1899) found in the livers of healthy 

 animals (cows, sheep, rabbits, guineapigs) diplococci and 

 chains of 3 or 4 cocci, which on culture yielded B. coli in 

 many cases. 



(3) No control experiments were conducted to exclude 

 the possibility of skin contamination at the site of the 

 inoculation, but such a supposition is inadequate to explain 

 all the results obtained. 



