THE EXTEKMINATION OF THE AMERICAN BISON. 401 



5. The Yearling. — During the first five months of his life, the calf 

 changes its coat completely, and becomes in appearance a totally differ- 

 ent animal. By the time he is six months old he has taken on all the 

 colors which distinguish him in after life, excepting that upon his fore 

 quarters. The hair on the head has started out to attain the luxuriant 

 length and density which is so conspicuous in the adult, and its general 

 color is a rich dark brown, shading to black under the chin and throat. 

 The fringe under the neck is long, straight, and black, and the under 

 parts, the back of the fore-arm, the outside of thigh, and the tail-tuft 

 are all black. 



The color of the shoulder, the side, and upper part of the hind quarter 

 is a peculiar smoky brown ("broccoli brown" of Kidgway), having in 

 connection with the darker browns of the other parts a peculiar faded 

 appearance, quite as if it were due to the bleaching power of the sun. 

 On the fore quarters there is none of the bright straw color so charac- 

 teristic of the adult animal. Along the top of the neck and shoulders, 

 however, this color has at last begun to show faintly. The hair on the 

 body is quite luxuriant, both in length and density, in both respects 

 quite equaliug, if not even surpassing, that of the finest adults. For 

 example, the hair on the side of the mounted yearling in the Museum 

 group has a length of 2 to 2£ inches, while that on the same region of 

 the adult bull, whose pelage is particularly fine, is recorded as being 2 

 inches only. 



The horn is a straight, conical spike from 4 to 6 inches long, accord- 

 ing to age, and perfectly black. The legs are proportionally longer and 

 larger in the joints than those of the full-grown animal. The counte- 

 nance of the yearling is quite interesting. The sleepy, helpless, inno- 

 cent expression of the very young calf has given place to a wide awake, 

 mischievous look, and he seems ready to break away and run at a sec- 

 oud's notice. 



The measurements of the yearling in the Museum group are as fol- 

 lows: 



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 I 11 



Depth of flank 1 1 



Girth behind fore leg 4 3 



From base of horns around end of nose 2 1£ 



Length of tail vertebra 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 per- 

 fectly straight, or with a curve near its base, and a straight point the 



H, Mis. 600, pt. 2 2G 



