s. A careful observer,
Rengger,[21] gives reasons for believing that a hairless dog was
domesticated when America was first visited by Europeans: some of these
dogs in Paraguay are still dumb, and Tschudi[22] states that they suffer
from cold in the Cordillera. This naked dog is, however, quite distinct
from that found preserved in the ancient Peruvian burial-places, and
described by Tschudi, under the name of _Canis Ingae_, as withstanding cold
well and as barking. It is not known whether these two distinct kinds of
dog are the descendants of native species, and it might be argued that when
man first migrated into America he brought with him from the Asiatic
continent dogs {24} which had not learned to bark; but this view does not
seem probable, as the natives along the line of their march from the north
reclaimed, as we have seen, at least two N. American species of Canidae.

Turning to the Old World, some European dogs closely resemble the wolf;
thus the shepherd dog of the plains of Hungary is white or reddish-brown,
has a sharp nose, short, erect ears, shaggy coat, and bushy tail, and so
much resembles a wolf that Mr. Paget, who gives this description, says he
has known a Hungarian mistake a wolf for one of his own dogs. Jeitteles,
also, remarks on the close similarity of the Hungarian dog and wolf.
Shepherd dogs in Italy must anciently have closely resembled wolves, for
Columella (vii. 12) advises that white dogs be kept, adding, "pastor album
probat, ne pro lupo canem feriat." Several accounts have been given of dogs
and wolves crossing naturally; and Pliny asserts that the Gauls tied their
female dogs in the woods that they might cross with wolves.[23] The
European wolf differs slightly from that of North America, and has been
ranked by many naturalists as a distinct species. The common wolf of India
is also by some esteemed as a third species, and here again we find a
marked resemblance between the pariah dogs of certain districts of India
and the Indian wolf.[24]

With respect to Jackals, Isidore Geoffroy Saint Hilaire[25] says that not
one constant difference can be pointed out between their structure and that
of the smaller races of dogs. They agree closely in habits: jackals, when
tamed and called by their {25} master, wag their tails, crouch, and throw
themselves on their backs; they smell at the tails of dogs, and void their
urine sideways.[26] A number of excellent naturalists, from the time of
Gueldenst