MUSCLES OF THE ABDOMEN 377 
costal cartilage, to the tenth and eleventh cartilages a little (ca. 1 to 2 em.) below 
the junction with the rib, to the twelfth rib at its ventral end and to the last rib 
below its middle. The cupola is very unsymmetrical; on the left side it is opposite 
the sixth rib, while on the right it is an intercostal space further back. 
MUSCLES OF THE BACK AND LOINS 
The serratus dorsalis anterior arises from the median raphé of the neck and the 
first six or seven thoracic spines, and is inserted into the second to the ninth ribs. 
It is well developed. The serratus dorsalis posterior—much weaker—arises from 
the lumbo-dorsal fascia, and is inserted into the last three or four ribs. Thus one 
or two ribs intervene between the two. 
The longissimus costarum is well developed, and extends from the ilium tothe 
sixth, fifth, or fourth cervical vertebra. 
The longissimus dorsi resembles that of the other animals, but the spinalis et 
semispinalis separates clearly from the longissimus proper at the sixth or seventh 
thoracic vertebra. It is inserted into the articular and spinous processes of the 
last six cervical vertebre. 
It has no depression in the 
lumbar region for the glu- 
teus medius. 
The intertransversales 
are fleshy, as in the ox. 
The interspinales are 
distinct and are most devel- 
oped in the lumbar region. 
MUSCLES OF THE TAIL 
These present the 
same general arrangement 
asin the horse. The sacro- 
coccygei, however, arise on 
the lumbar vertebr2 also, 
and the coccygeus on the 
1, Ilium; 2, femur; 3, tuber ischii; 4, sacro-sciatic ligament; 5, sacral 
ischiatic spine. There Is a region; 6, tail; 7, penis; 8, anus; 9, rectum; a, sacro-coccygeus dorsalis; 
Sacro-coccygeuS acceSssor- b, sacro-coceygeus accessorius; c,'coccygeus; d, sacro-coceygeus ventralis; e, 
ius which arises on the retractor ani; /f, /’, sphincter ani externus; g, retractor penis; A, bulbo- 
i l b f t ili cavernosus; i, transversus perinei (?); &, m, ischio-urethrales; J, ischio- 
media order of the ium, cavernosus; n, tendon of obturator internus; 0, [gemellus, p, urethral 
the edge of the sacrum, and = muscle. ( After Ellenberger, in Leisering’s Atlas.) 
the transverse processes of 
the first coceygeal vertebre, and is inserted between the dorsal and lateral sacro- 
coceygei. It is homologous with the intertransversales. 
Fic. 325.—Muscies oF Tarr, Anus, AND GentTat OrGans oF Doe. 
MUSCLES OF THE ABDOMEN 
The abdominal tunic is practically absent. 
The obliquus abdominis externus has an extensive fleshy part. It arises from 
the last eight or nine ribs and the lumbo-dorsal fascia. 
The obliquus abdominis internus arises from the tuber coxe and the lumbo- 
dorsal fascia. The fibers have an almost vertical direction, and there is a fleshy at- 
