MUSCLES OF THE BODY. 147 
Insertion (Fig. 81, @) into the humerus along.a line which 
forms the ventral border of the bicipital groove at the proximal 
end of the bone, passes thence onto the pectoral ridge and 
continues in the direction of the pectoral ridge nearly as far as 
the middle of the length of the humerus. The cranial and 
caudal fibres are inserted by means of a thin tendon; the 
middle fibres directly. The cranial border of the tendon of 
insertion is continued as a thin tendon to the coracoid process ; 
it is closely united with the insertion of the supraspinatus. 
Relations.—By its outer surface with the pectoralis major 
(Fig. 65, 7) over its cranial half; with the cutaneus maximus, 
latissimus dorsi (Fig. 65, g), and integument over its caudal 
half. By its inner surface with the xiphihumeralis (Fig. 65, ), 
rectus abdominis (Fig. 73, 2), and a mass of fat in the axilla. 
The tendon of the xiphihumeralis is also connected with its 
inner surface near its insertion. Its cranial border is free. Its 
caudal border is in relation at its medial end with the xiphi- 
humeralis, at its lateral end with the tendon of the latissimus 
dorsi (Fig. 65, ¢). 
Actton.—Draws the arm toward the middle line. 
M. xiphihumeralis (Fig. 65, 7).—A long, thin, narrow 
muscle which may be considered as part of the pectoralis 
minor. 
Origin a median raphe along the xiphoid process or at an 
angle to the median line on the rectus abdominis muscle. It 
passes craniad, becoming gradually smaller, and about two 
centimeters from its insertion ends in a thin tendon. 
/nsertion.—It ends in a flat tendon which in passing is con- 
nected by a strong fascia with the tendon of the latissimus 
(Fig. 65, ¢). It passes along the inner surface of the pectoralis 
minor (0) to be inserted with its cranial fibres near the ventral 
border of the bicipital groove. 
Relations.—Outer surface with the cutaneus maximus at 
its medial end, with the pectoralis minor (¢) at its distal end. 
Inner surface with the external oblique (Fig. 68, #), the rectus 
abdominis (Fig. 73, £), and a mass of fat in the axilla. Borders 
free. Some of the fibres of the cutaneus maximus are attached 
to its outer surface. 
