The opening of the small intestine into the large is by a narrow slit called the ileo-caecal valve. By the time that the chyle enters the large intestine, its fluid particles and the large amount of intestinal juice thrown out by the crypts of Lieberkuhn have been absorbed, and it has assumed a pasty consistence and has acquired an offensive faecal odour. The faeces contained in the large intestine consist of the indigestible remnants of the food, and various excretory materials thrown into the alimentary canal during the process of digestion. The undigested substances are the woody and fibrous parts of vegetable food, the elastic fibres and tissues or gristle and the insufficiently cooked parts of animal food. This collection of excrementitious materials, being of no use whatever to the economy, is gradually passed along the large intestine, and is thrown out of the body by the rectum.

Fig. 5. - Tubular Glands of the Large Intestine, Magnified 40 Diameters.

A. Tubular glands seen sideways and from above, showing their substance and their mouths.

B. The same seen sideways and from below, showing their substance and their terminal culs-de-sac.