92 IMMUNITY IN HEALTH 



So, too, tabes mesenterica may be unaccompanied by 

 obvious disease of the Peyer's patches. Caseating ileo- 

 colic glands may exist with a normal vermiform 

 appendix. 



It would seem as if the subepithelial lymphatic 

 glands had an especially high resistance to the tubercle 

 bacillus, but that occasionally a lymphocyte loaded 

 with tubercle bacilli would pass to the nearest intersti- 

 tial gland and there be overcome by its contained 

 bacilli, and a tuberculous focus thus be set up. Or 

 possibly the ingested but undigested tubercle bacilli 

 live so slowly that their relatively inert forms have been 

 transferred to adjacent interstitial glands before their 

 effects begin to be produced. 



It is as a rule only when the general resistance has 

 been greatly lowered, as in the last stages of phthisis, 

 that tuberculous ulcers on the tonsil are found, though 

 tuberculous disease is found in a certain proportion of 

 enlarged tonsils that have been excised. 



