THE DIGESTIVE SYSTEM. 553 



queut exceptions. Tuberculous ulcers rarely perforate. (See for other 

 forms of tuberculosis of the intestine page 560.') 



Syphilitic Ulcers, originating in the lymphatic structures, are sometimes 

 found in infantile syphilis. 



Duodenal Ulcers may be tuberculous or may follow extensive burns. 



FIG. 329. SuBSEROfs TUBERCLES FOLLOWING THE LYMPH-VESSELS AT THE BOTTOM OF A TUBERCULOUS 

 ULCER OF THE SMALL INTESTINE. 



In the latter case their mode of origin is obscure. They may occur under 

 a variety of other conditions. 2 



Other Forms of Ulcers. The solitary and agminated lymph-nodules 

 frequently undergo hyperplasia, in infectious diseases, after extensive 



FIG. 330. TUBERCULOUS ULCERS OF THE SMALL INTESTINE. 

 Showing the extension of the ulcers in a direction transverse to the axis of the gut. 



burns, in various forms of inflammation of the intestine. Hyperplasia 

 of the lymphatic tissue see above with ulceration is especially frequent 

 in children. 



1 For statistics of intestinal tuberculosis see Zahn, Munch, med. Woch., Jan. 14th, 

 1902; also Nebelthau, ibid., July 1st and 28th, 1903; also Wagener, Munch, med. Woch., 

 Nov. 24th and Dec. 1st, 1903. For presence of tubercle bacilli in mesenteric lymph- 

 nodes see Nacfadyen and Macconkey, Br. Med. Jour., July 18th, 1903. 



2 For a study of duodenal ulcers see Weir, Medical Record, May 5th, 1900, bib- 

 liography. 



