516 CHORDATA. 
condition of a simple jointed lever. Thus in each case the 
ulna and fibula tend to disappear, their remains or vestiges 
being seen along the border of the radius and tibia respec- 
tively. The carpal bones are reduced to six in each case, 
and the tarsals to five or six in the horse and to four in 
the ox. In addition, the two rows are firmly interlocked 
Fig. 354.—Tue Ricut Manus Fig. 355.—Tue RicuT Manus 
or A Horse. (Ad nat.) OF AN Oxx 4. (Ad nat.) 
Anterior View x }. Cuneiform. Lunare. 
ne one Pisiform. Seacihotl, 
sissies kg Scaphoid. 
5 Si Magnum. 
Unciform. fe! qian at Magnu 
4 Unciform. 
Os Magnum. |. 
v 
it F Metacarpal 5. 
Third 4 
Mctacarpal. od 
Cannon-bone. 
Phalanx tr. 
Phalanx 2. 
Phalanx of 
Digit 4. 
* Phalanx 3. 
and lie alternately with each other (dip/arthrous) to prevent 
all lateral twisting. The mode of locomotion is digitigrade, 
the toes alone touching the ground, and the metacarpals and 
metatarsals are reduced in number and elongated. The 
terminal phalanx or phalanges bear horny hoofs. 
With all these general resemblances we can note such 
important differences that it is an easy matter to distinguish 
