MUSCLES OF THE ANTEBIOB LIMBS. 



279 



D. Muscles of the Anterior Foot in Eaminants. 



These animals have no muscles, properly speaking, in the region of the foot ; in fact, 

 we only find in them the supensory ligament of the fetlock, which is the interosseous of 

 the two complete digits. 



COMPAEISON OP THE HAND OT MAN WITH THAT OP ANIMALS. 



The muscles of Man's hand are numerous and well-developed, in consequence of the 

 extent and variety of the movements of its various parts. They are divided into three 

 groups: the external, or group of the thenar eminence, induce the movements of the 

 thumb ; the internal, or group of the hypothenar eminence, those of the little finger ; and 

 the middle group, occupying the metacarpal spaces, comprising the interosseous muscles, 

 In addition, there is found in the hand a cuticularis muscle, the cutaneous palraaris 

 (palmaris hrevis). 



The cutaneous palmaris occupies two-thirds of the hypothenar eminence ; its fibres 

 are directed downwards and iuwards. It corrugates the skin on the ulnar border of the 

 hand. 



A. Muscles of the Thenar Eminence. 

 These muscles, nearly all present in the Dog, 

 are; 



1. The short adductor of the thumb, whose 

 fibres, leaving the lower portion of the anti- 

 brachial aponeurosis, the process of the trape- 

 zius and the scaphoides, are succeeded by a ten- 

 don which is inserted into the upper extremity 

 of the first phalanx of the thumb. 



2. The opponent {opponens) of the thumb, 

 which passes from the anterior part of the tra- 

 pezium to the external border, and near the 

 anterior face of the first metacarpal. 



3. The shcyrt flexor of the thumb, a muscle 

 adjoining the preceding, and which is resolved 

 into two series of fibres — a deep and a super- 

 ficial. 



4. The short adductor of the thumb, a trian- 

 gular muscle, occupying the outer half of the 

 hollow of the palm. It is attached to the os 

 magnum, along the entire length of the third 

 metacarpal bone and, by a tendon, to the sesa- 

 moid and supero-internal tuberosity of the first 

 phalanx of the thumb. 



B. Muscles of the Sypofhenar Eminence. 



These muscles are : 1. The abductor of the 

 little finger, a small fusiform muscular body, 

 which is attached, above, to the pisiform bone, 

 and below to the supero-internal part of the 

 first phalanx. 



2. The short flexor of the little finger, situ- 

 ated without the preceding, fixed in one part 

 to the process of the unciform bone, and in the 

 other to the inner part of the first phalanx. 



3. The opponent (opponens) of the little finger, 

 a triangular muscle, situated below the pre- 

 ceding. It is inserted into the process of the 

 unciform bone, then into the inner border of 

 the fifth metacarpal and the adjacent portion of its 



Fig. 128. 



MUSCLES OP HUMAN HAND. 

 , Annular ligament ; 2, 2, Origin and in- 

 sertion of the abductor pollicis muscle ; 

 3, Flexor ossis metacarpi, or opponens 

 pollicis ; 5, Deep portion of flexor brevis 

 pollicis; 6, Adductor pollicis; 7, 7,Ltim- 

 bricales muscles arising from the deep 

 flexor tendons, upon wliicli the figures 

 are placed ; 8, A tendon of deep flexor ; 

 9, Tendon of flexor longus pollicis ; 10, 

 Abductor minimi digitii; 11, Flexor 

 brevis minimi digitii; 12, Pisiform 

 bone; 13, First dorsal interosseous 

 muscle, the abductor indicis. 



anterior face. 



C. Interosseous Muscles, 

 " The interosseous muscles are situated in each interosseous space, two for each space, 

 and are divided into dorsal and palmar. As there are four interosseous spaces, there ought 

 to be eight muscles ; but it is usual to exclude the short adductor of the thumb, because 



