The Mule Deer, (_Odocoileus hemionus._)—This fine animal is universally known throughout the Rocky Mountain region, which constitutes its home, as the “Black-Tailed Deer.” Because of its very large ears, _and the absence of a black tail_, it is known to naturalists as the Mule Deer. Inasmuch as its tail is not black, the above more common name properly applies to _Odocoileus columbianus_, the true black-tailed deer of the Pacific coast. In Manitoba this animal is called the “Jumping Deer,” because when running at a gallop, it makes a series of stiff-legged jumps, or “bucks,” of great length. The weight of full-grown bucks ranges from 250 to 300 pounds, and specimens have been known to reach 325 pounds. The antlers of the Mule Deer are larger and handsomer than those of the white-tailed deer, and are much better poised on the head. Instead of dropping forward, they partake more of the set of an elk’s antlers, and many a “tenderfoot” hunter has mistaken a heavily-antlered Mule Deer for an elk. The antlers of a Mule Deer are easily distinguished from those of the white-tailed species by the two Y-shaped prongs on each antler. It will be remembered that instead of these, the white-tailed deer antler bears three straight, perpendicular spikes. The Mule Deer makes its home in rugged ravines and bad lands so common along the creeks and rivers of the Rocky Mountain region, extending well eastward into the plains. Of late years it has been driven out of the most accessible of its former haunts, and forced to take shelter in the rugged fastnesses of the foothills and mountains. West of the Rocky Mountains it was formerly found along the whole Pacific slope, from Cape St. Lucas to British Columbia, although in northern California it is almost replaced by the Columbian Black-Tail, (_O. columbianus_). DEVELOPMENT OF THE ANTLERS OF A MALE DEER. These pictures show the stages of growth of the antlers from the time the old ones are dropped, to the full development. Number 1 shows the bull with the one antler gone—picture made early in March. Number 6 shows the full grown antlers, with the velvet hanging in strips. Number 6 was made August 24 of the same year as Number 1. This remarkable antler development takes place every year in the life of all male deer. [Illustration: 1.] [Illustration: 2.] [Illustration: 3.] [Illustration: 4.] [Illustration: 5.] [Illustration: 6.]