Caecum and appendix anatomy, 19th-century illustration. The cutaway section at left shows the caecum, the start of the large intestine. Food from the final section of the small intestine (the ileum) passes into the caecum through the ileocaecal valve (centre). At lower left is the appendix, a tube-like structure that may be vestigial but may play a role in maintaining healthy gut flora. Published in 'La Vie Normale et la Sante' (Normal Life and Health, Paris, 1881) by Dr Jules Rengade.