MUSCULAR SYSTEIM. 83 



lateral parts of the abdomen ; whose fibres, generally, run in a 

 longitudinal plane, from before backwards, from the shoulder to 

 the flank : as they approach this latter part, they converge, and 

 finally become collected into a broad, thick, muscular band, 

 which is included within the fold of skin forming the border of 

 the flank, and ends upon the front of the haunch, interwoven 

 with the faschia covering that part, by which it is fixed to the 

 patella. Anteriorly, the abdominal is connected with the tho- 

 racic portion by an aponeurotic intervention ; along its superior 

 border, the faschia covering the back and loins attaches the 

 muscle to the spine ; inferiorly, it becomes gradually indistin- 

 guishable from the faschia superficialis abdominis, with which it 

 is blended, and through which it gets an attachment to the 

 pubes. The spur-vein is seen ramifying, superficially, upon this 

 portion of the muscle. 



Relations. — The strongest fibres of the panniculus are exhibit- 

 ed by its abdominal portion : the palest and weakest are seen 

 upon the face. Its cervical portion is in many places intimately 

 blended with the levator humeri ; and also with the pectoral 

 muscles. The thoracic part envelopes the trapezius, rhomboidei, 

 latissimus dorsi, and spinati muscles ; the abdominal portion 

 covers the external oblique muscle and its aponeurosis. 



Altachments. — Besides those already mentioned, it is loosely 

 and partially connected, by cellular substance, with the several 

 muscles and bones and ligaments which it immediately covers ; 

 but everywhere intimately and generally with the skin. 



Direction. — Upon the head its fibres ramify in an arborescent 

 form ; upon the neck they take an oblique course ; upon the 

 shoulder they run in a perpendicular direction ; upon the abdomen, 

 in a horizontal line. 



Action. — The contractions of the panniculus throw the skin 

 into folds or corrugations, transversely in the direction of its 

 fibres ; so that the one form right angles with the other. The 

 chief points from which it acts, are the lower jaw, the scapula 

 and head of the humerus, the patella, and the pubes. By sud- 

 denly and repeatedly wrinkling his skin, the horse (unprovided 

 with hands for the purpose) effects the dislodgement of insects 

 which annoy him, and likewise of any irritating or noxious sub- 

 stance, such as thorns or prickles, dirt, hayseeds, &,c. This power 

 also enables him to resist, to a certain degree, the gripe or bite of 

 an adversary. And so habitual does this cutaneous action become, 

 that, although perfectly and fully at the command of the will, it 

 often appears to take place involuntarily, or at least unheeded by 

 the animal : this is particularly remarkable at the time that a 

 horse is grazing or feeding, and is the while annoyed by Hies. 



