DISSECTION OP THE ANTERIOR LIMB. 27 



Directions. — In this stage of the dissection the student will be better 

 able to trace the musculo-cutaneous branch of the median nerve, and the 

 insertions of the biceps and brachialis anticus muscles (see pages 1 6 and 

 ,19). When these have been examined, he may, as the next step, either 

 dissect the articulations of the shoulder and elbow (pages 41 and 43), or 

 he may saturate the parts already dissected with some preservative solu- 

 tion, and postpone the examination of these joints till after the dissec- 

 tion of the metacarpus and digit. 



THE METACARPUS AND DIGIT. 



The distal portion of the horse's fore limb, beyond the lower extremity 

 of the radius, is technically termed the manus, as it corresponds to the 

 hand of man. The carpus, or, as it is commonly but erroneously 

 termed, the knee, of the horse corresponds to the wrist of the human 

 subject. The portion of the limb between the carpus and the fetlock, 

 representing the palmar portion of man's hand, is called the metacarpus ; 

 while the rest of the limb, beyond the fetlock, is the digit, and is the 

 homologue of man's middle-finger. 



Surf ace-tnar kin ff. — By flexing the carpal and fetlock joints, the splint 

 bones may be felt at the back of the metacarpus. Behind the bones in 

 the same region lie the flexor tendons, the subcarpal ligament, and the 

 suspensory ligament. These, whose edges may be more or less distinctly 

 seen in a well-bred animal, have the relation to each other shown in 

 Plate 7. Behind the fetlock-joint is a tuft of hair in which will be 

 found a horny spur or ergot, which is largest in coarse-bred animals. 

 By manipulation, the flexike lateral cartilages may be felt above the 

 hoof, in the region of the heels. 



Directions.— The entire remaining portion of skin should now be care- 

 fully removed from the limb. Should it be intended to study from the 

 same preparation the parts contained within the hoof, this must, before 

 the removal of the skin, be detached by force in the manner described 

 on page 35. The various structures are now to be defined by dissection 

 in the order of the following description ; and while the vessels and 

 nerves are being cleaned, care must be taken of the small lumbricales 

 muscles, which lie on the tendon of the deep flexor above the fetlock. 

 The palmar arterial' arches cannot be fully exposed at this stage of the 

 dissection, but it is convenient to describe them here, from their 

 relationship to the vessels of the region. The same applies to the 

 large metacarpal artery and the plantar nerves behind the carpus 

 all of which can be fully traced in the examination of the carpal sheath 



^^fhe^ l'aege Metacarpal Artery (Plate 9). This is the largest 

 artery in the part of the limb now exposed, and is, by means of its ter- 



