does in quadrupeds, according to the species. Some are altogether
carnivorous; others, as so many of the web-footed tribes, subsist on
fish; others, again, on insects and worms; and others on grain and
fruit. The extraordinary powers of the gizzard of the granivorous
tribes, in comminuting their food so as to prepare it for digestion,
would, were they not supported by incontrovertible facts founded on
experiment, appear to exceed all credibility. Tin tubes, full of grain,
have been forced into the stomachs of turkeys, and in twenty-four hours
have been found broken, compressed, and distorted into every shape.
Twelve small lancets, very sharp both at the point and edges, have been
fixed in a ball of lead, covered with a case of paper, and given to a
turkey-cock, and left in its stomach for eight hours. After that time
the stomach was opened, when nothing appeared except the naked ball. The
twelve lancets were broken to pieces, whilst the stomach remained
perfectly sound and entire. From these facts, it is concluded that the
stones, so frequently found in the stomachs of the feathered tribes, are
highly useful in assisting the gastric juices to grind down the grain
and other hard substances which constitute their food. The stones,
themselves, being also ground down and separated by the powerful action
of the gizzard, are mixed with the food, and, no doubt, contribute very
greatly to the health, as well as to the nourishment of the animals.