A, H, from the nape to the insertion of the throat into the maxillary trough; And H, B, from this latter point to the margins of the lips. [Illustration: FIG. 110.--PROPORTIONS OF THE HEAD OF THE HORSE, SEEN FROM THE FRONT (AFTER COLONEL DUHOUSSET).] =The Head, Front View= (Fig. 110).--If, to continue our examination, adds M. Duhousset, we regard the head from the front, we find its greatest width at A, B, the extreme points of the orbital arches. This width is 22 centimetres. It is again equal to: A, C, from one arch to the nape; A, D, from one arch to the middle of the face. D, E, from the middle of the face to the margin of the lips. From the auditory canal, G, to the maxillary spine, F, is the same distance as from this point to the margins of the lips, E, or, better, to the end of the teeth. [Illustration: FIG. 111.--THE SAME FIGURE AS FIG. 110, ON WHICH WE HAVE MARKED BY SIMILAR LINES THE PRINCIPAL MEASUREMENTS WHICH CORRESPOND THERETO. Distance which separates one of the orbital arches from that of the opposite side, and the dimensions which equal it; distance which separates the auditory meatus from the maxillary spine, and the dimensions which equal it; distance which separates one maxillary spine from that of the opposite side, and the dimensions which equal it; distance which separates the lip of one side from that of the opposite, and the dimensions which equal it.[65]] [65] See the note relative to Fig. 109. The line G, C, from the auditory meatus to the nape, is equal to the sixth of the head, 10 centimetres; the line A, G, from the orbital arch to the auditory meatus, is a little longer, and measures 12 centimetres. The distance F, I, comprised between the maxillary spines, is 18 centimetres. It is equal to: O, O, the distance between the internal angles of the eyes (G. and B.); F, R, the distance from the maxillary spine to the superior commissure of the corresponding nostril (G. and. B.); F, P, from the maxillary spine to the _salt-cellar_.[66] [66] We designate under the name _salt-cellar_ a depression situated external to the frontal region and above the eye. From the nape to the internal angle of the eye, C, O, is the same distance as from this latter point to the commissure of the lips, O, T; and from the maxillary spine to the upper lip F, S (G. and B.).