PATHOGENIC BACTERIA. 359 



surfaces and become widely scattered throughout a cavity like 

 that of the pleura or peritoneum. The bacilli may be expelled 

 on some mucous surface and be carried along it to infect some 

 point farther on, as happens when the larynx becomes infected 

 in tuberculosis of the lung, and when in the same disease 

 tuberculous sputum is swallowed and leads to infection of the 

 intestines. Finally, the infectious material may enter the 

 blood-vessels, especially the veins, and be swept along with 

 the blood-current to become scattered generally throughout 

 the body. In such cases we are likely to have general or acute 

 miliary tuberculosis. Almost every organ of the human body 

 may be infected by tuberculosis. Among the most common 

 may be mentioned the lungs, the lymph-nodes, the bones, the 

 intestines, the skin, the meninges, and the serous membranes. 



Harbitz* found as a result of his observations that primary 

 tuberculosis of the lymph glands is quite frequent in adults, 

 not only in the thorax, but also in the abdomen, and especially 

 in the cervical nodes, often it is generally distributed in the 

 lymphatic system having extended through years and tens of 

 years. 



Infection, as far as we know, is always to be attributed 

 directly or indirectly to some preexisting case of tuberculosis 

 in man or the lower animals. 



The mode of entry into the body of both man and animals 

 is a matter of liveliest dispute; some holding with Fliigge that 

 the commonest mode of entrance is by way of inhalation 

 into the lungs; others maintaining with Behring that the 

 entrance is always by the alimentary tract, f Those who hold 

 the latter view have this much to present in evidence that, as 

 Raven el showed, the tubercle bacillus may pass through the 



*Journ. Infect. Dis. Vol. II. 1905. pp. 143-247. 



fVarious bulletins of the Department of Agriculture. Revenel. Journal 

 of Medical Research. X., p. 460. Ibid. Transactions of the American Public 

 Health Association. XXIX. Calmette and Guerin. Annales de I' Institute 

 Pasteur. III., p. 1024, IV., p. 636. 



