4 ANATOMY OF THE HORSE. 



CERTAIN TERMS used in descriptive anatomi/ may re- 

 quire some explanation. 



The anatomist views the body in the erect position ; the limbs 

 preserving, in the direction of the tendency of the weight, per- 

 pendicular lines in respect to the trunk, and parallel lines in re- 

 gard to the correspondent fore and hind feet, and also, in the 

 transverse direction, in relation to one foot to its fellow ; the 

 head and neck maintaining theirnatural degrees of elevation and 

 curvature; the tail erect. In this position, the anatomist as- 

 sumes, to aid him in his descriptions, that an imaginary plane 

 extends through the body, bisecting it into lateral halves ; this 

 is continued through the neck and head, and descends between 

 the legs. The correlative terms, superior- and inferior, anterior 

 and posterior, require no elucidation, unless it be in regard to 

 the head and neck : the line bounding the superior regions is 

 considered to extend from the tip of the coccyx over the occiput 

 to the upper lip ; that forming the inferior boundary, from the 

 lower lip, along the under jaw, down the neck, and along the 

 belly, with some interruption in the croup, to the extremity of 

 the tail. The adoption of the compounds of these terms, leads 

 to still further accuracy in description : such are antero-superior, 

 antero-inferior, supero-anterior, infero-anterior, &c. Antero-supe- 

 rior denotes the anterior compartment of the superior region : 

 supero-anterior, the superior compartment of the anterior region ; 

 and so on. Inner and outer express relation to the bisecting 

 plane, running through the middle, median or mesian, region: 

 but the compounds mesio-superior, rnesio-posterior, &c. have no 

 reference whatever to the middle regions : they simply imply 

 the middle compartments of the superior and posterior regions. 

 According to this arrangement, every distinct part, the head, 

 neck, shoulder, quarter, arm, thigh, &c. is divided, by imagi- 

 nary lines, into five regions : — superior, inferior, anterior, poste- 

 rior, and middle ; each of which is subdivisible into three minor 

 compartments: e.g. the superior region is distinguishable, if 

 lequired, into antero superior, mesio-superior, and postero- 

 superior ; the anterior into supero-anterior, mesio-anterior, and 

 infero-anterior; and so with the others. Without this explana- 

 tion the anatomical detail, to follow, might prove perplexing 

 or even unintelligible: by such preparation, the labour of the 

 anatomist is abridged and facilitated ; the progress of the stu- 

 dent smoothed and accelerated. 



OF THE TRUNK. 



The trunk coniprchcndb the vertebral chain, the thorax, and 

 the pelvis. 



