Elephants: Aiding digestion
The two members of the order Proboscidea; the African and IndianElephant (Loxodonta africana and Elephas maximus) have particularly acute problems for they eat, in addition leaves, a great deal of fibroustwigs and woodymaterial. Apart from their tusks their only teeth are molars at the back of the mouth, which form massive grinders. As they wear down they are replaced every few years by new ones erupting from behind and migrating forward along the jaw. The molars pulp and crush with enormous power, but even so, the elephants food is so woody it requires a very long period of digestion to extract anything of value from it. The elephant's stomach, however, is big enough to provide it. A meal taken by a human being normally passes through the body in about twenty-four hours. An elephant's takes about two and a half days to make the same journey and for most of that time it is kept stewing in the digestive juices and bacterial broth of the stomach. Much earlier in history some dinosaurs, eating ferns and cycads, had encountered the same problem and solved it the same way by becoming giants.