A. Period of Support of the Hind Legs at the Gallop. 



Figure 5 represents a hind leg at the gallop, from the 

 time it arrives on the ground until it leaves the ground, 

 that is to say, during the whole period of propulsive 

 effort. 



The study of the angles with the horizon of the various 

 radii and of the variations of the angles at the joints dur- 

 ing this period show : 



a. The inclination of the ilium to the horizontal has 

 the following values : 



Position o 42°. 5 



I 38° 



2 32°.5 



3 29°. 



4 25°. 5 



b. The inclination of the femur to the horizontal is as 

 follows : 



Position o 65° 



I 70° 



2 81° 



3 85° 



4 87° 



Note that at position 4 the leg has just left the ground, 

 the femur is beginning to close again towards horizontal- 

 ity, and there has been very probably between position 3 

 and position 4 an intermediate position which has not 

 been seized by the camera, and where the inclination 

 of the femur to the horizontal was more than 87°. We, 

 therefore, shall not consider position 4 in our argument. 



c. Variations of the coxo-femoral angle : 

 Position o i07°-5 



I 108° 



2 113°. 5 



37 



