POINTS FROM WHICH THE PROPORTIONS ARE STUDIED. 365 



As to that which concerns the comparative proportions of man and 

 horse, the reader may gather information from Fig. 130, which repre- 

 sents a man of 1.70 m. mounted upon a horse of 1.60 m. The latter 

 is in the position of rassembler, ready to begin the step.^ 



B.— Angular Relations of the Osseous Segments. 



Besides the relations of length, width, and thickness which exist 

 between the different regions of the body, it is also important to know 

 the relations of direction possessed by the diiferent bony regions super- 

 posed one upon the other to form the members. These relations, as 

 we have seen, have an influence upon the production of speed and force. 



From this mode of superposition, angles are produced upon the 

 course of the various bones, whose summit always corresponds to the 

 centre of movement of an articulation, and whose sinus is either in the 

 anterior or the posterior part of the particular region. 



But as the bones of the skeleton have a variable external configura- 

 tion, and as their axis of figure does not always terminate in an artic- 

 ular centre, — witness the femur, whose surfaces of contact with the 

 pelvis and the tibia are situated internal to and behind the median line 

 of the bone, — it follows that we can logically determine the angles of 

 locomotion only after having previously ascertained the axis of move- 

 ment of each of their branches. Now, the latter are obtained by simply 

 uniting to each other the articular centres, which are at the same time 

 the centres of rotation of the said branches. All researches not founded 

 upon this experimental mode are therefore at once condemned as being 

 vitiated by arbitrariness and error. The analysis of the following 

 theory will give the proof. 



Theory of the Similitude of the Angles and the Parallel- 

 ism of the Bony Segments. — More than half a century ago, in 

 1835, Captain Morris,^ later commanding general of the Imperial Guard, 

 published a pamphlet in which was expressed the opinion that in all 

 well-formed horses the same articular angles had a uniform opening or 

 size and the osseous segments inclined in the same direction, — were parallel 

 Again, these bony segments were inclined at an angle of Jf5 degrees to 

 the horizon. Whence it follows that the head, the shoulder, the thigh, 

 and the pastern on one hand ; the neck, the humerus, the croup, and 

 the lee- on the other, in order to combine the conditions of beauty, were 



1 For further details, see E. Duhousset, Etude sur les proportions du cheval, d'aprte son 

 ossature, in Illustration, nos. des 18-25, Aotit et ler Septembre, 1883. 



2 Capitaine Morris, Essai sur I'Ext^rieur du cheval, Paris, 1835, chez Mme. Huzard, rue de 

 TEperon. 



