j7i v 1 ///: KDB< LE8, 



It is a very delicate baud, situated in front, ami un tin- inner side of tin- anterior 



-<>r of the metacarpus, taking its origin, along with t.iat muscle, t'rum tli 

 limiting the furrow of torsion of the hum. -ins, In-hind the ridire; ami i< rminating 

 within tin- inferior extremity of the radius by fleshy anil ajMincurotie libre-i. This Miiill 

 muscle can have but a very limited influence on the movements of the bom-s "f the 

 fore-arm, Ix/cause of its trilling volume. A> it- name indic.iti-. it acts in supimition. 



3. Short Supinutor (Fig. 1'J."., 11, 2.) 



A triangular and slightly divergent nniM-lr. covered l.y the anterior extenflor of the 

 metacarpus and the coiiuuou extensor of the digits. It has its origin in the small 

 situated outside the humeral trochloa. by a flat tendon which is c mfoumled with the. 

 external lateral ligament of the ellw joint. It terminates above the anterior face and 

 the inner side of the nulius, by the inferior extremities of its fle.shy film-. r<,\,-nd l.y 

 the two preceding muscles, it covers the elbow articulation and the Ixmu rcceivi 

 in-ei lion. It ought to be considered, in Garni vora, as the principal supinator; it pivots 

 the radius on the ulna, so as to turn the anterior face of the first bone outwards. 



4. Round Pronator. (Fig. 125, B, 1 ; c, 1.) 



Situated on the inner and upper part of the fore arm, between the great palmar or 

 internal flexor of the metacarpus and the interior extensor of the same ray, the numd 

 pronator is a thick and fhort muscle, which originates on the small epicondyloid 

 tuberoeity of the hutuerus, and terminates at the internal side of the radius by aponeu- 

 rotic fibres. 



5. Square Pronator. (Fig. 125, c, 2.) 



This muscle is situated immediately behind the bones of the fore-arm, beneath the 

 muscular masses of the jxisterior antibrachial region. It extends from the insertion of the 

 tlexors of the fore-arm to near the carpus, and is formed of transverse tibres which pass 

 dinc'ly from the ulna to the radius. It is, 'lien, no longer, as in Man, a square nnisclo 

 attached only to the lower fourth of these two bones. The twopronators are antagonists 

 of the short supinator, turning forwards the anterior face of the radius and metacarpus. 



COMPARISON OF THE MUSCLES OF THE FORE-ABM OF MAN WITH THOSE OF ANIMALS. 



All the muscles of the fore-arm of Man are more or less perfectly represented in the 

 fore-arm of Carnivoia. 



In Man, these muscles are described in placing the fore-arm in a state of supination, 

 and are divided into three regions : anterior, external, and posterior. 



A. Anterior Region. 



This comprises eight muscles : 



1. The round pronator, absent in animals except the Garni vora. This muscle forms 

 the internal oblique prominence in the bend of the elbow. It leaves the epitmchh-a and 

 the coronoid process of the ulna, terminating on the middle third of the external face of 

 the ratlins. 



2. The yreat palmaris, which corresponds to the internal flexor of the metae n-pus of 

 the Horse. Situated within the preceding, it is attached, above, to the epitrochl.a; 

 below, to the base of the second metacarpal. It is more especially a flexor of Un- 

 hand. 



3. The small palmaris, whose presence is not constant, and which is represented in 

 the Dog by a portion of the deep flexor of the phalanges. 



ratus ; 1', Its tendon divided at its passage behind the carpal sheath ; 2, Do., Its 

 terminal branches ; 3, Perforans ; 3', Its tendon divided after its exit from the 

 carpal sheath ; 4, Do., Its terminal branches ; 5, Tendon of the internal flexor of the 

 metacarpus ; 6, Oblique flexor (anterior ulnar) ; 7, Inferior extremity of the long 

 supinator; 8, Terminal tendon of the oblique extensor of the metacarpus ; 9, 

 Short abductor of the thumb; 10, Opponent of the thumb; 11, Short flexor of 

 the thumb; 12, Adductor of the thumb, transformed, in the Dog, into the adduc- 

 tor of the index; 13, Short flexor of the small digit; 14, Adductor of the small 

 digit; 15, Opponent of the small digit; 16, 16, Metacarpal interosseous muscles; 

 a, a, a, Bandit which maintain the flexor tendons on the metacarpo-phahmgean 

 articulations, and limit the separation of the digits ; collectively, they represent, 

 in a rudimentary state, the palmar aponeurosis of Man. 



