The family is undoubtedly of old world origin, and for the most part
belongs to the northern hemisphere, South America being the only
continental area in which they are found south of the equator.

The analytical habit of mind which finds vent in the subdivision of
species, is also exhibited in a tendency to break up large genera into a
number of small ones, but in the present group this practice has the
disadvantage of obscuring a broad distinction between the dominant types
inhabiting respectively the old world and the new. The former,
represented by the genus _Cervus_, has a brow-tine to the antlers;
has the posterior portion of the nasal chamber undivided by the vertical
plate of the vomer; and the upper ends only of the lateral metacarpals
remain, whereas in all these particulars the typical American deer are
exactly opposite. As there are objections to considering these
characters as of family value, arising from the intermediate position of
the circumpolar genera _Alces_ and _Rangifer_, as well as the
water deer and the roe, a broader meaning is given to classification by
retaining the comprehensive genera _Cervus_ and _Mazama_, and
recognizing the subordinate divisions only as sub-genera.

The one representative of _Cervus_ inhabiting America is the
wapiti, or "elk" (_C. canadensis_), which is without doubt an
immigrant from Asia by way of Alaska, and it may be of interest to state
the grounds upon which this conclusion rests, as they afford an
excellent example of the way in which such results are reached. It is an
accepted truth in geographical distribution, that the portion of the
earth in which the greatest number of forms differentiated from one type
are to be found, is almost always the region in which that type had its
origin. Now, out of about a dozen species and sub-species of wapiti and
red deer to which names have been given, not less than eight are