TUBERCULOSIS OF THE LYMPHATIC GLANDS. 177 



lymph current. As long as the infection has not extended along 

 the entire length of the chain of lymphatic glands the patient is 

 protected against miliary tuberculosis, but as soon as the virus has 

 passed all the lymphatic filters, and has direct access into the tho- 

 racic duct, miliary tuberculosis follows as an inevitable result by the 

 entrance of the bacilli into the general circulation. 



Weigert (" Die Verbreitungswege des Tuberkelgifts nach dessen 

 Eintritt in den Organismus," Jahrb. f. Kinderheilkunde, B. xxi. S. 

 146), in his description of the process of dissemination in cases of 

 acute miliary tuberculosis, has pointed out that in some cases the 

 bacilli are conveyed through the lymphatic system successively 

 until they reach the general circulation, while in others, and by far 

 the greater number, generalization of the tuberculous process takes 

 place more directly by the entrance of tubercular products through 

 a vein, an occurrence which is followed at once by rapid and exten- 

 sive diffusion by embolism. When the bacilli of tuberculosis have 

 reached the systemic circulation, the intensity of symptoms and the 

 subsequent course of the disease depend on the number of bacilli 

 which the blood contains. 



Weichselbaum (" Ueber Tuberkel-bacillen im Blute bei allge- 

 meiner acuter Miliartuberculose," Anz. d. ges. Wimerarzte, 1384, 

 No. 1 9), starting with the idea advanced by Weigert that every 

 acute miliary tuberculosis is caused by the direct entrance of the 

 tuberculous virus into a vein or indirect entrance along the lym- 

 phatic channels and through the thoracic duct into a vein, examined 

 the blood of three such, and found that it contained numerous bacilli. 

 In the lymphatic glands the tubercular process pursues a typical 

 pathological course. According to the rapidity of tissue-prolifera- 

 tion, or in proportion to the number of bacilli present, the granu- 

 lation tissue which is always the first and constant product of 

 tubercular inflammation undergoes caseation, and at an early stage 

 often numerous centres can be seen from where the retrograde 

 degenerative changes take their starting-point. By confluence of 

 such caseous foci the entire gland is formed into a cheesy mass. 

 Liquefaction of such caseous material results in the formation 

 of a fluid which macroscopically resembles pus, but under the 

 microscope it presents only the product of retrograde tissue-trans- 

 formation, and no well-defined pus corpuscles, and none of the 

 microorganisms which are known to produce suppuration can be 

 obtained by cultivation experiments, showing conclusively that the 

 fluid possesses no pyogeuic properties. The bacillus of tuberculosis 

 finds in the granulation tissue a soil well adapted to its growth and 

 development, but, as soon as caseation takes place, its culture soil 

 in that portion of the gland has been destroyed, and its field of 

 growth is limited to the surrounding zone of granulation tissue, in 



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