MUSCLES OF THE ANTEItlOR LIMBS. 341 



InteroBseons muscles, and concealed Vjy the tendinous portion of the rommon flexor of the 

 digits, this muscle is attached, superiorly, to the posterior carpal ligament with the third 

 interosseous muscle. It is fixed, iuferiorly, by means of a small flattened tendon, along the 

 superior and internal side of the first phalanx of the index. It is regarded as the adductor of 

 the thumb in Man transformed into an adductor of the index, in consequence of the atrophy of 

 the fifth digit. 



5. CcTANEors Palmar (Palmaris Brevis). 



A thick, hemispherical, musculo-adipose body, forming the base of tho exterior tubercle 

 placed behind the carpus. It adheres intimately to the skin by its superficial face, and deeply 

 to the aponeurosis covering the muscles of the hand. 



6. Adductor of the Small Digit (Fig. 188, d, 14). 



This muscle is superficially situated, external to, and behind the outer metacarpal bone, and 

 is composed of a thick, conical fleshy body, concave on its anterior surface, convex posteriorly, 

 and of a long, thin, and flat tendon, which succeeds the inferior extremity of the muscular 

 portion. 



It is att.iclied, by the superior extremity of the latter, to the pisiform bone; the tendon 

 terminates outsi le the superior extremity of tiie first phalanx of the small digit. 



This muscle separates that digit from the axis of the hand, and is therefore an abductor 

 and not an adductor, as its name would indicate. That name has been given to it in Man, 

 because the hand has been considered in a state of supination, a position in which it is 

 eftectively an adductor in regard to tlie median plane of the body. If this name has been 

 preserved here, it is owing to a desire not to import any new element of confusion into a 

 nomenclature already too complicated. 



7. Short Flexor of the Small Digit (Fig. 188, d, 13). 



Situated within the preceding, in a slightly oblique direction downwards and outwards, 

 flattened before and behind, triangular, and almost entirely muscular, this muscle derives its 

 origin from a ligament which unites the pisiform bone to the metacarpal region, and terminates 

 inferiorly on tiie tendon of the adductor, whose congener it is. It may also concur in the 

 flexion of the small digit, tliough to a very limited degree. 



8. Opponent of the Small Digit (Fig. 188, d, 15). 



A muscle elongated from above downwards, flattened before and behind, situated under the 

 perforans tendons, behind tlie second interosseous muscle, in a direction sligiitly downwards 

 and outwards. It originates from the posterior ligament of the carpus, and terminates within 

 the superior extremity of the first phalanx of the external digit by a small tendon. It acts as 

 an adductor by drawing the small digit towards the axis of the hand. 



9. I.UMBRICr. 



These small muscles, which owe tlieir name to the resemblance they bear to the lumbricales 

 or earthworms, are only three in number in Carnivora. They occupy the interval between the 

 four chief branches of the perforans ten' ion, fiom which they have their origin ; they terminate, 

 by a small fibrous digitation, on the extensor tendons of the three external digits. It is often 

 impossible to trace them so far; for they are frequently observed to stop within and above the 

 first phalanx of the digits for which they are destined. Their functions cannot be rigorously 

 defined in Carnivora. 



10. Metacarpa Interosseous Muscles (Fig. 188, d, 16, 16). 



These are four thick and prismatic muscular fasciculi, elongated from above to below, 

 bifid at their inferior extremity, placed parallel to one another, in front of the flexor 

 tendons, from which they are separated by a thin aponeurotic layer, and behind the four large 

 metacarpals. 



They have their origin on tlie posterior and lateral faces of these bones, as well as on the 

 posterior carpal and intermetacarpal ligaments. Eacii terminates, by the two branches of its 

 inferior extremity, on the great sesamoids of the digit to which it corresponds. There they are 

 continued by a small tendon, which joins the chief extensor of the digit. These muscles 

 oppose undue extension of the digits while the animal is standing, flex tln-m on the metacarpal 

 bones, and maintain the extensor tendons on the anterior aspect of the phalanges. 



