152 



NORMAL HISTOLOGY. 



tributed to the muscles and other structural elements. These fibres 

 are of the non-medullated variety. 



The nerves of the panereas are also non-medullated, possess a 

 few ganglia within the organ, and are finally distributed among the 

 epithelial cells. 



The Tonsils, Lymph-follicles, and Peyer's Patches. — These collee- 

 tions of lymphadenoid tissue in the alimentary tract have special 



Fig. LSI. 



I 



%■■ . ■ 



4 



\s% 



Section through one of the crypts of the tonsil. (Stohr.) e, stratified epithelium of the gen- 

 eral surface, continued into the crypt:/, follicles containing germinal foci. Between 

 the follicles is a more diffusely arranged lymphadenoid tissue, s, material within the 

 crypt, composed in part of lymphoid corpuscles that have wandered through the strati- 

 tied epithelium. 



interest to the physician as being points particularly liable to infec- 

 tion. The solitary follicles of the stomach and of the small and 

 large intestine, and the collections of such follicles forming the 

 patches of Peyer, are the sites which are most vulnerable to 

 invasion by pathogenic bacteria in the digestive tract, though they 

 are probably protected to a considerable extent by the germicidal 

 powers of the acid gastric juice. This is not always capable of 

 guarding them from infection by the typhoid and tubercle bacilli,, 



