i6 
ANIMALS IN MOTION. 
position to the body and to the other limbs as it occupied 
at the commencement of the notation. 
The normal stride of a biped consists of two uniformly 
executed steps. 
Shakespeare recognizes this fact in The Merchant of 
Venice, act iii. sc. 4— 
“ I'll . . . turn two mincing steps 
Into a manly stride.” 
The normal stride of a quadruped, while using four 
limbs as supports, during locomotion, consists of four steps. 
These steps may occur singly, and at approximately 
regular periods of time, as in the walk; singly, and at 
irregular periods, as in the amble, the canter, or the gallop ; 
or in pairs, as in the trot or in the rack. 
To facilitate a study of the various systems of support 
and propulsion employed by an animal during the execu¬ 
tion of any of its regular gaits, symbols have been adopted 
to designate the feet which during the instant of a 
particular phase are actually engaged in one or both of 
these special functions. 
These symbols are for—- 
Left. 
Right. 
Anterior, or fore feet 
A 
▲ 
Posterior, or hind feet ... 
O 
• 
Denotes that the left fore-foot and the right 
hind-foot are at that instant being used to support 
or to propel the body. 
A 
Denotes a transit without, at that instant, the 
actual support of any one of the feet. 
In the diagrams, arrowdieads indicate the direction 
of the movement. The sequences of the phases are 
regularly numbered. 
The intervals of time or of distance between any two 
phases of the diagrams are not there recorded, nor is the 
precise locality of any foot indicated. These facts can 
only be ascertained by reference to the illustrations from 
which the diagrams are constructed. 
In the execution of the eight distinct systems of 
regular progressive motion, animals employ fifteen different 
methods of temporary support, all of which are, under 
various conditions, made use of by the horse. They are— 
A- -L 
O'* 
Four feet on the ground. 
A A A A 
L A--A A--A 
O'# o--# o— 
2345 
Three feet on the ground. 
