502 O. C. Marsh—Polydactyle Horses. 
in Cuba. He is known among showmen as the “ Hight-footed 
Cuban Horse.” With the exception of the extra digits, he is 
well-formed, and doubtless is capable of considerable speed, 
although some of the exploits claimed for him may fairly be 
questioned. 
The four main hoofs are of the ordinary form and size. The 
extra digits are all on the inside, and correspond to the index 
finger of the human hand. They are less than half the size 
of the principal toes, and none of them reach the ground. An 
external examination indicates that the metapodial bone of 
each extra digit is entire, and at its lower end, at least, is 
not codssified with the main cannon bone. 
There appear to be two phalanges above the coffin bone in 
each of these digits, which are thus rendered flexible, especially 
in a fore and aft direction. There was no indication of ‘‘inter- 
fering” shown on the inner digits themselves, although it is 
difficult to see how this could be entirely avoided during rapid 
motion. The splint bone on the outer side of each leg is 
apparently of the usual shape and size. 
Among the instances of recent polydactyle horses, described 
to the writer by those who have seen them, are two of special 
interest. One of these was a colt with three toes on one fore 
foot, and two on the other. The animal recently died in Ohio. 
Another is a mare, raised in Indiana, and still living, which is 
said to have three toes on each fore foot, and a small extra 
digit on each hind foot. In regard to the latter animal, the 
writer hopes soon to have more definite information. 
Besides the instances mentioned above of extra digits in 
place. in the existing horse, there are many cases on record of 
true monstrosities, as, for example, additional feet or limbs 
attached to various portions of the body. Such deformities 
now admit of classification and explanation, but need not be 
considered in the present discussion. 
In reviewing what is now known of extra digits in the feet 
of the modern horse, the best authenticated instances appear 
to fall naturally into two groups. The first of these includes 
digits which are simply cases of reduplication, quite similar to 
the extra finger occasionally seen in the human hand. Sue 
deformities are apparently a vegetative repetition, the explana- 
tion of which has not yet been satisfactorily determined. The 
second class includes cases where a true digit is formed, the 
component bones of which are in their normal position, and in 
proper relation to the rest of the limb. Such instances appear 
to be clearly due to reversion to some ancestral.type. Som 
_ digits, which appear at first sight to belong in the first category, 
_ may really illustrate the second, but the converse of this is 
