PATHOLOGICAL RESULTS, ETC. 345 



lous material, even though this may be slightly virulent in 

 nature, and this affection through the pharynx occurs with- 

 out the production of a local lesion and reproduces what are 

 known as scrofulous glands in the neck of human beings. 

 It is also seen that from these tuberculous glands below the 

 jaw the disease in some instances spreads down the cervical 

 glands and affects the lungs by way of the bronchial glands : 

 an exact reproduction of some cases of pulmonary tubercu- 

 losis in the human being. The proportion of cases in the 

 human being in which intestinal infection occurs is probably 

 greatly under-estimated, and the results of post-mortem ex- 

 aminations are frequently misread, owing to the fact that 

 extensive disease in the lungs leads us to the conclusion 

 that the disease was primary there, the lesion in the in- 

 testine being very slight. As regards the infection of the 

 lungs in the human being, it may be ascribed to four modes 

 of infection. When primary, it is due to inhalation of tuber- 

 culous material in a dried state ; when secondary, it may 

 spread downwards from the primary affection of the glands 

 below the jaw ; thirdly, it may spread upwards from 

 the intestines without affection of the intervening glands ; 

 and, fourthly, it may occur from the presence of an active 

 focus elsewhere, either in a joint or bone. 



Tuberculosis of the lymphatic glands in the thorax, the 

 bronchial and posterior mediastinal glands, is not an 

 uncommon affection in children. Experiment appears to 

 show that the commonest modes of infection are either 

 from scrofulous glands in the neck or from the intestines, 

 and. as in the experiments" on the calf, the lesion in the 

 intestine may be slight and the lesion in the thorax great. 

 It is possible, however, that the bronchial glands might be 

 affected by the inhalation of a small dose of tuberculous 

 material through the lung itself, no local lesion in the lung 

 tissue being produced. This, however, is purely theoretical, 

 since I am not aware of any experiments in which the 

 inhalation of small quantities of tuberculous material has 

 produced this effect. 



As regards the other lesions in the human being which 

 result from intestinal infection, the chief of which is tuber- 



