PATHOLOGY 77 



and other pathogenic bacteria could exist harmlessly 

 next to the tissues unless the body possessed some 

 method of more or less neutralising the effects of always 

 possible invasions. 



It is noteworthy that it is not only in man that the 

 subepithelial lymphatic glands are liable to disease. As 

 might be expected, this side of the question has hardly 

 been explored, but Hett has observed tonsils "like 

 a child's unhealthy tonsils" in one Rhesus monkey 

 and in one young gorilla ; actinomycosis in a Kan- 

 garoo's tonsil ; a large cyst in a hyena's tonsil ; tuber- 

 culous disease in several monkeys' tonsils, whilst Mr. 

 Stapley, in a personal letter to me, has written : — 



"I have never seen an inflamed appendix in a wom- 

 bat, but I have seen several wombats that have died 

 from perforation of a Peyer's patch that was within 

 an inch of the ileo-csecal valve." 



