THE 
VETERINARIAN. 
VOL. III. 
JULY, 1830. 
No. 31. 
ANATOMY OF THE HORSE. 
[Continued from page 304.] 
2.—A EDO M INAL REGION. 
An intervening stratum of cellular substance attaches the 
abdominal portion of the panniculus carnosus to a glistening ex¬ 
pansion of tendon, situated underneath it, which is the aponeu¬ 
rosis of the external oblique muscle. This cellular substance 
being removed, several white lines, marked upon the subjacent 
tendon, come into view. The principal of these is one which 
runs along the middle of the belly, extending from the ensiform 
cartilage to the pubes : it takes the name of linea alba ; and de¬ 
notes the line of junction and demarcation between the abdomi¬ 
nal muscles on one side and those of the other. About midway 
between its two terminations, this line has a perforation, the um- 
bilicus or navel, through which passes the umbilical chord. At 
some short distance from the sides of the linea alba are two 
curved or waving lines, called the linea semilunares: they mark 
the line of union between the fleshy and tendinous fibres of the 
external oblique muscle. Traversing the interspaces between the 
linea alba and linese semilunares, at short intervals from one ano¬ 
ther, are several transverse lines, named the linea transversales: 
they are produced (as will hereafter be discovered) by the ten¬ 
dinous intersections across the straight muscles; and are, in 
some subjects, but obscurely marked. 
There are four pairs of abdominal muscles: —two pairs of oblique 
muscles; one pair of transverse ; and one pair of straight mus¬ 
cles. Three of these pairs are ranged in strata, one upon another, 
and have sheets of tendon connected with them, which take the 
name of aponeuroses . 
obliquus externus abdominis. — ( Costo-abdomina/is. ) 
Situation .—Upon the inferior and lateral parts of the belly. 
Figure . — Broad, thin ; quadrilateral. 
vol. in. 3 c 
