66 E VOL VTION AND DISEASE. 



ways : The communication with the caecum may 

 become obliterated, and the tube distend into a cyst 

 in consequence of fluid accumulating within it ; such a 

 cyst may rupture, and lead to minor troubles, as local 

 inflammation or abscess, or induce death by peritonitis. 

 Adenoid, or lymphatic, tissue is very prone to ulcerate, 

 and under certain conditions the adenoid tissue lining 

 the appendix may inflame and lead to fatal perforation. 

 A much commoner danger is the entrance into it of such 

 things as fruit-stones and similar indigestible sub- 

 stances taken with the food ; these 

 act as irritants, and in the long run 

 destroy life. A somewhat similar 

 condition of things may be studied 

 in lions and tigers. In these hand- 

 some animals there is no vermiform 

 appendix, and the caecum is even 

 more vestigial than in man. This 

 FIG. 33--The vermiform smajl caecum occasionally contains 



appendix of a Silvery 



Gibbon (Hyiobates leu- a concretion having a fragment of 

 bone, a nail, or piece of wood for the 

 nucleus. Concretions in the vestigial caecum of the 

 tiger produce similar effects to cherry-stones, &c,, in 

 the human vermiform appendix, and on two occasions I 

 have been able to connect such concretions with the 

 fatal illness of tigers. 



Although a small and insignificant caecum is not 

 always an advantage, it is on the other hand a disad- 

 vantage to have one too large. The horse will illustrate 

 this : it has a caecum measuring, on an average, one 

 metre in length, and a capacity equal to thirty-five litres 



