d by the
chemical constituents of food, although they are not without a positive
influence. Evidently the preparation of food has much to do with man's
progress, and the art of cooking was a great step in advance. The
better utilization of food was a time-saving process--and, indeed, in
many instances may have been a life-saving affair.

_The Domestication of Animals_.--The time and place of the
domestication of animals are not satisfactorily determined. We know
that Paleolithic man had domesticated the dog, and probably for
centuries this was the only animal domesticated; but it is known that
low forest tribes have tamed monkeys and parrots for pets, and savage
tribes frequently have a band of dogs for hunting game or guarding the
hut. While it may be supposed that domestication of animals may have
occurred in the prehistoric period, the use of such animals has been in
the historic period. There are many evidences of the domesticated dog
at the beginning of the Neolithic period. However, these animals may
have still been nearly half wild. It is not until the period of the
Lake Dwellings of Switzerland that we can discriminate between the wild
animals and those that have been tamed. In the Lake Dwelling debris
are found the bones of the wild bull, or _urus_, of Europe. Probably
this large, long-horned animal was then in a wild state, and had been
hunted for food. Alongside of these remains are those of a small,
short-horned animal, supposed to have been domesticated. Later, though
still in the Neolithic period, remains of short-horned tame cattle
appear in the refuse of the Lake Dwellings. It is thought by some that
these two varieties--the long-horned _urus_ and the short-horned
domesticated animal brought from the south--were crossed, which gave
rise to the origin of the present stock of modern cattle in central
Europe. Pigs and sheep were probably domesticated in Asia {93} and
brought into Europe during the later Neolithic or early Bronze period.

The horse was domesticated in Asia, and Clark Wissler[1] shows that to
be one great centre of cultural distribution for this animal. It
spread from Asia into Europe, and from Europe into America. The llama
was early domesticated in South America. The American turkey had its
native home in Mexico, the hen in Asia. The dog, though domesticated
very early in Asia, has gone wherever the human race has migrated, as
the constant companion of man. The horse, whi