Avenues of Infection 73 



Various organisms pass from the pharynx to the tonsils and so 

 to the lymph-nodes and deeper tissues of the neck, where their first 

 operations may be observed. 



It is supposed by some pathologists that the digestive tract is a 

 constant menace to health in that it regularly admits bacteria, 

 through the lacteals, and perhaps through its capillaries, to the 

 blood, where under slightly abnormal conditions they might do 

 harm. According to Adami,* the intestine is responsible for a 

 condition of sub-infection depending upon the constant entrance 

 of colon bacilli into the blood. He finds the colon bacillus in 

 the blood, and traces it to the liver, where its final dissolution 

 takes place in the fine dumbbell-like granules enclosed in the 

 cells. NichoUsf confirms Adami by finding similar dumbbell 

 or diplococcoid bodies in the epithelial denuded tissues of the 

 mesentery of normal animals. 



Nicholas and DescosJ and Ravenel§ fed fasting dogs upon a soup 

 containing quantities of tubercle bacilli, killed them three hours 

 later, and examined the contents of the thoracic duct, where 

 tubercle bacilli, some alive and some dead, were found in large 

 numbers, van Steenberghe and Grysezjl found that carbon particles 

 readily passed through the intestinal mucosa, entered the lymphatics, 

 were thrown into the venous circulation, and so carried to the lung, 

 where anthracosis was produced. 



In a subsequent paper** they believe that they have demonstrated 

 that the tubercle bacillus like the carbon particles may also pass 

 through the normal intestinal wall, and follow the same course to 

 the lungs. They believe that pulmonary tuberculosis thus depends 

 upon ingested and not inhaled micro-organisms. Montgomery ft re- 

 peated the work of van Steenberghe and Grysez at the Henry Phipps 

 Institute, Philadelphia, but though many attempts were made by 

 various methods, no carbon particles seemed to be transported from 

 the alimentary to the pulmonary tissues. 



But there are enough experiments recorded to make it probable 

 that the wall of the intestine is permeable to bacteria, and that in 

 small numbers they constantly enter the blood of healthy animals, 

 to be disposed of by mechanisms yet to be described. 



Many of the bacteria penetrating the intestine must be retained 

 in the lymph nodes; others, as in the experiment with the tubercle 

 bacilli, meet destruction before they reach the blood; the remainder 

 must reach the blood alive. 



The presence of colon bacilli in the greater number of the organs 



*"Jour. of the American Medical Association," Dec. 16 and 23, i8g9, vol. 

 xxxm, Nov. 25 and 26. 



t "lour. Med. Research," vol. xi, No. 2. 



t"Jour. de Phys. et Path. g6n.," IQ02, iv, 910-912. 



§ "Jour. Med. Research," 1904, x, p. 460. 



||"Ann. de I'lnst. Pasteur," Dec. 25, 1905, Tomexix, No. 12, p. 787. 

 **Ibid., ipio, XXIV, 316. 

 tt "Jour, of Med. Research," Aug., 1910, vol. xxin, No. i. 



