382 DISEASES OF THE OASTRO-INTESTINAL TRACT. 



been produced in lower animals by the injection of dysenteric 

 stools into their intestines. 



The severity of the lesions noted varies greatly. In mild 

 cases the mucous membrane is swollen and hypersemic, and 



FIG. 173. 



Appendix containing biliary calculus (Museum, Carnegie Laboratory). 1, biliary 



calculus. 



covered with tenacious mucus. The solitary follicles are 

 enlarged, and petechial hemorrhages are often seen. At a 

 later stage and in more severe cases these follicles undergo 



