Zone Map of North America. 
The United States Biological Survey has just 
issued its fourth Provisional Zone Map of North 
America, to which are attached the names C. 
Hart Merriam, Vernon Bailey, E. W. Nelson and 
E. A.. Preble. 
It is many a long year since Dr. Merriam pub¬ 
lished his first map . of life zones in Western 
America, and ever since that time he has been 
working on this subject and directing investiga¬ 
tors and students in this same work. The re¬ 
sults we have before us‘in a remarkably com¬ 
plete and useful map covering America from the 
Arctic south through Panama, which should be 
in the hands of everyone who is interested in 
biology in any form. Certainly it should be 
owned by every sportsman. 
By this map North America is divided into 
three great regions, the Boreal, Austral and 
Tropical. The Boreal region is divided into 
Arctic, Hudsonian and Canadian zones; the 
Arctic taking in the extreme north of North 
America including the shores of Bering Sea, of 
Hudson's Bay. down nearly to its southern end, 
and a small tongue which runs down in the 
mountains on the borders of the Canadian Prov¬ 
inces of Yukon and Mackenzie. The Hudsonian 
includes Northern British America, including the 
northern half of Newfoundland, Ungava, part of 
Quebec, Northern Keewatiif and Northern Brit¬ 
ish Columbia. It is also found on high moun¬ 
tain peaks in the Rockies and the Coast Range. 
The remainder of Canada together with Maine, 
Northern Michigan and Wisconsin, and many 
high peaks in the mountains are Canadian. The 
northern United States with a great bay includ¬ 
ing parts of Manitoba, Alberta and Saskatche¬ 
wan are in the upper division of the Austral 
region which is called the Transition, while the 
two other zones of the Austral region called 
Upper Austral and the Lower Austral take up 
the rest of the United States, running down to 
Mexico. The extreme point of Florida, the coast- 
region of Mexico, Central America and part of 
Lower California are Tropical. 
Of course since altitude stands for latitude, 
high mountains rising out of lower country form 
little islands of a colder zone surrounded by a 
ring of the next milder zone and this by a great 
expense of still another zone. 
The zone divisions of the Austral region- — 
Transition. LTpper Austral and Lower Austral — 
extending as they do across the continent, in¬ 
clude regions both humid and arid. The zones 
to the east of the great plains are marked with 
dots which. indicate the extent of the humid 
divisions of these zdnes, which humid divisions 
are known respectively as the Alleghanian. Caro¬ 
linian and Austroriparian faunas. The dry, un- 
'dotted portions of the same zones are known as 
Transition Upper Sonoran and Lower Sonoran 
The sportsman or student who will provide 
himself with one of these maps and will go over 
it State by State and Province by Province; 
studying mountain range, lake and river system, 
will learn much that is very interesting and useful. 
CROSSING HORNS 
NORMAL HORNS. 
Unusual Antelope Horns. 
Last autumn I saw a pair of antelope horns 
unlike any that have ever come under my obser¬ 
vation and quite worthy of brief description. 
It is well understood that the antelope is the 
only hollow-horned animal that sheds its horns. 
These consist of a bony core covered by a 
horny sheath; in other words, its horns are like 
those of a cow. It does not shed the horns in 
the sense in which the deer sheds its antlers. 
Antlers, when they have completed their growth 
and the velvet has been lost from them, are 
mere dead bones which drop off after a few 
months. In the horns of the antelope on the 
other hand, only the sheath is shed, the living 
bony processes from the skull remaining un¬ 
changed through life. Like other bone, these 
processes are covered with periosteum, over 
which there is a skin which, as the summer ad¬ 
vances, becomes thicker and covered with hair. 
Over this skin fits the hollow black horn sheath, 
and as autumn approaches, this hollow horn 
sheath is pushed away by the new growth of 
hair on the skin which covers the bony horn 
core, so that if one kills an antelope in autumn 
or early winter, the horn sheaths may readily be 
pulled away from the head, leaving bare the skin 
which covers the horn core, which skin is now 
covered with white hair and is soft and warm 
to the touch. Sometimes when an antelope is 
killed at this season, one or both sheaths drop 
off at the mere shock of the animal s fall. Only 
at the tip of the horn is the new horn sheath 
hard and black. As time goes on, the hairs 
covering the skin become agglutinated together 
and turn black, and there is a new horn sheath 
scarcely differing in appearance from the old 
one. In other words, the deer, when it sheds it-5 
antlers, loses a bony outgrowth, while the ante>- 
lope loses a dermal outgrowth. 
As is well known, the hooked tips, of the horns 
of the antelope usually turn backward, or some¬ 
times .inward, so that the point of each horn is 
directed toward the point of the horn on the 
other side of the head. I have one pair—the 
only ones I ever saw—that turn inward, forward 
and downward with a deep hook. 1 he spread 
of the horns varies considerably, and occasion¬ 
ally a pair is seen where the horns are directed 
almost outward from the sides of the head. In 
old times when antelope were enormously abund¬ 
ant, one was occasionally found in which one 
horn or the other was “crumpled”; that is to 
say, bent dowm over the face or by the side of 
the muzzle, or both horns were bent outward 
and down turned on either side. I have always 
rather taken it for granted that such cases were 
the result of some injury, perhaps the breaking 
or bending of the horn core from some cause or 
other. 
It is easy to see that if an antelope received 
in anv wav a blow on the horns hard enough to 
break the bone, the horn might hang down over 
the face or side of the head, the bone ultimately 
knit together and the ordinary processes of 
shedding and growing new horn sheaths take 
