342 O. C. Marsh — Recent Polydactyly Horses. 



(4) With the extra inner toes of the fore feet, another of 

 equal or smaller size may be present on one or both of the 

 hind feet, almost always on the inside. Usually, however, 

 these posterior toes are much smaller, and often beneath the 

 skin, when the anterior extra digits are well developed. An 

 example of the equal development of all the inner toes, fore 

 and aft, is shown below in figure 6, which represents an animal 

 examined during life, by the writer. Occasionally the hind 

 feet may each have two extra digits, while the fore feet have 

 only one, as in the horse shown in figure 7. 



(5) In rare cases, both fore and hind feet may each have two 

 extra digits fairly developed, and all of nearly equal size, thus 

 corresponding to the feet of the extinct Protohippus, which 

 are represented in the diagram on page 355. 



(6) Sometimes, besides the extra toes above described 

 (which appear to be always the second and fourth), the first 

 digit, or pollex, may be represented by its metacarpal, sup- 

 ported by a distinct trapezium, all beneath the skin. In such 

 cases, the fifth digit, corresponding to the little finger of the 

 human hand, alone is wanting. Three examples of this four- 

 toed polydactylism are preserved in the Yale Museum, and one 

 of them is shown in figure 3. This type is of special impor- 

 tance, and is described more fully below. 



The horse which best represents this type was examined 

 casually by the writer when it was alive, and at its death 

 was presented to him for the Yale Museum by the owner, 

 Theodore F. Wood, of New Jersey. The animal was widely 

 known to the general public as "Clique, the horse with six 

 feet," having been exhibited for many years, in this country 

 and in Europe. He was said to be from Texas, and at his death, 

 in January, 1891, was very old. This horse, when alive, showed 

 an extra digit of good size on the inside of each fore foot, and 

 a corresponding prominence on each of the hind feet, but no 

 free lateral toe. An outline of this horse is shown in figure 5. 



The first digit of the fore foot, corresponding to the thumb 

 of the human hand, was not apparent externallj 7 , butj by close 

 examination, could be detected beneath the skin, where the 

 upper part of the splint bone appeared as a ridge. The second 

 digit was the free extra toe, which attracted especial attention 

 from its large size, and pendent, elongated hoof. Its meta- 

 tarsal is closely united to the main cannon bone, which thus 

 seems much broader than usual. The fourth digit appears 

 only as the usual splint bone, and of the fifth, there is no 

 indication whatever. The hind feet showed no peculiarity ex- 

 cept the inner prominence above the fetlock, formed by the 

 lower end of the second metatarsal, with a single movable 



