order of events in the act of rumination: "The
paunch contracts, and in so doing forces some of the food into the
honeycomb bag, where it is formed into a bolus by the movement of
its walls, and then forced into the gullet, from which by a reverse
action it reaches the mouth, where it is chewed and mixed with the
saliva until it becomes quite pulpy, whereupon it is again swallowed.
But now, because it is soft and semi-fluid, it does not devaricate
the walls of the groove communicating with the manyplies, and so,
continuing on along its tubular interior, it finds its way direct
into the third stomach, most of it filtering between the membrous
laminae on its way to the fourth stomach, where it becomes acted on
by the gastric juice. After the remasticated food has reached the
manyplies, the groove in the reticulum is pushed open by a fresh bolus,
and so the process is repeated until the food consumed has all passed
on towards the abomasum or true digestive stomach."

The ruminants are peculiar also in their dentition; in the so-called
true ruminants there are no incisors or cutting teeth in the upper
jaw, but the teeth of the lower jaw are opposed to a hard callous
pad; the herbage is cropped by being nipped between these teeth and
the pad, and detached by an upward motion; in some few, such as the
musk deer, Chinese water deer and the rib-faced deer or muntjac the
upper canines exist, and are largely developed.

The camels and llamas possess two cutting teeth in the upper jaw,
and in this respect they differ from the true ruminants, as also in
some internal features.

The grinding teeth are six on each side of the jaw, and are composed
of alternate convolutions of enamel, dentine and cement, which wear
unequally by the lateral motion of grinding, and so form the
necessary inequality of surface.

The centre metacarpal bones in the Ruminantia are fused into one
common bone, except in the deerlets, which also have the two outer
fore and little finger metacarpals distinct, whereas they are but
rudimentary in the rest of the true ruminants, and totally absent
in the camels.

The following is the classification at present adopted: SUB-ORDER
_Ruminantia_, containing two sections, viz. True Ruminants and the
Camels (_Tylopoda_). SECTION _True Ruminants_, containing two
divisions, viz. Horned Ruminants and Hornless Ruminants, such as the
chevrotians or deerlets (_Tragulidae_). DIVISION Horned Ruminants,
containing two grou