+----------------------------------------------------------------+ |BISON AMERICANUS. (Male yearling, taken Oct. 31, 1886. Montana.)| +----------------------------------------------------------------+ | (_No. 15694, National Museum collection._) | +----------------------------------------------------------------+ | | Feet.| Inches. | |Height at shoulders | 3 | 5 | |Length, head and body to insertion of tail | 5 | | |Depth of chest | 1 | 11 | |Depth of flank | 1 | 1 | |Girth behind fore leg | 4 | 3 | |From base of horns around end of nose | 2 | 11/2 | |Length of tail vertebræ | | 10 | +----------------------------------------------------------------+ 6. _The Spike Bull._--In hunters' parlance, the male buffalo between the "yearling" age and four years is called a "spike" bull, in recognition of the fact that up to the latter period the horn is a spike, either perfectly straight, or with a curve near its base, and a straight point the rest of the way up. The curve of the horn is generally hidden in the hair, and the only part visible is the straight, terminal spike. Usually the spike points diverge from each other, but often they are parallel, and also perpendicular. In the fourth year, however, the points of the horns begin to curve inward toward each other, describing equal arcs of the same circle, as if they were going to meet over the top of the head. In the handsome young "spike" bull in the Museum group, the hair on the shoulders has begun to take on the length, the light color, and tufted appearance of the adult, beginning at the highest point of the hump and gradually spreading. Immediately back of this light patch the hair is long, but dark and woolly in appearance. The leg tufts have doubled in length, and reveal the character of the growth that may be finally expected. The beard has greatly lengthened, as also has the hair upon the bridge of the nose, the forehead, ears, jaws, and all other portions of the head except the cheeks. The "spike" period of a buffalo is a most interesting one. Like a seventeen-year-old boy, the young bull shows his youth in so many ways it is always conspicuous, and his countenance is so suggestive of a half-bearded youth it fixes the interest to a marked degree. He is active, alert, and suspicious, and when he makes up his mind to run the hunter may as well give up the chase.