MUSCLES OF THE TRUNK. 211 



^..Z^U '■'ff ^''^'^T '.« J'ifi'3' «s ill t'le smaller quadrupeds. Less developed than in these 

 animal the a»3« am is only fixed in front to the four first cervical vertebraB. 

 «.w 7 *?f^.™»» 13 large, hut by its insertions it resembles that of Solipeds. The 



great compUxusWnok and broad above, is incompletely divided into two fleshy bodies 

 which are attached superiorly, to the sides of tlie external occipital crest. The smoa 



trmastoid process. '"'" '"^^ ""'' "'^'^ '^*'"^' "^ ^"P^"°' ^^'^^^"^ P^^^^^S ^-^<='^ *» 



of tte^!6ai'■°thSp?pnnl?'fvf *° S?*^^^!f 'li°g ihB straight posteri^ and oSKg^e m«sc?e8 

 bines in this r^giof ^^ "" ^'"^ *"™ ''"' *^"^^*° "'^ conformation of the 



„„i^!i?^- *'^° *""*?■ T^i"' muscles, that which corresponds to the anterior serrated of 

 ?WK 1 fi! f^f ^ iigli; for It IS attached by an aponeurosis to the spinous processes of 

 the thiee first dorsal vertebras, the seventh cervical, and the cervical ligament. 



Ihere are found in Man, lying along the vertebral furrows, several muscles which 

 represent the iho-spinalis and the common intercostal of Solipeds. Thus the common 

 mass covering the lumbar vertebras behind, is prolonged by two series of fleshy and ten- 

 dinous iasciculi: one forms i):ie sacro-lmnbalis, which resembles th.B common intercostal 

 ot animals; the other, the long dorsal, represents the inferior branch of the ilio-spinalis. 

 ihe superior branch of the latter is found in the transversalis colli. 



Lastly, there are also seen in Man a, transverse spinal and inteHranmerse muscUs, 

 which con-espond : the first, to the transverse spinous of the bach and loins and transverse 

 spinous of tlie neck ; the second, to the intertransversaUs of the loins of the domesticated 

 species. 



B. Muscles of the Nedlc. 



The mastoido-humeralis is not present in Man, being peculiar to quadrupeds; but we 

 should see a portion of its fasciculi in the cleido-mastoideus muscle, and in the clavicular 

 portions of the trapezius and deltoid. 



The stemo-mastoideus corresponds to the sterno-maxillaris of animals; as in the Dog, 

 it is inserted into the external face of the mastoid process and the external two-thirds of 

 the superior occipital curved iine. Below, it commences by two fasciculi— one from tlie 

 sternum, the' other from the clavicle. We have already alluded to this clavicular 

 fasciculus. 



The sterno-hyoideus and sterno-thyroideius are large and well developed, resembling in 

 their disposition those of the smaller animals. It is to be noted that the sterno-hyoideus 

 leaves the sternum, the first costal cartilage, and the internal extremity of the clavicle. 

 The scapulo-hyoideus is digastric. The anterior great straight muscle of the head is 

 attached to tour cervical vertebrae, as in Euminants and the Pig. The anterior small 

 straight, the lateral small straight, and tlie long muscle of ihe neck, comport themselves as 

 in the smaller animals. The anterior scalenus is very developed, for it is attached to the 

 six last cervical vertebrae. 



SUBLUMBAB, OE INFEEIOK LTJMBAK REGION. 



The muscles of this region are deeply situated at the inferior face of the 

 lumbar vertebrae and the ilium, concurring to form the roof of the abdominal 

 cavity, and are in more or less direct contact with the viscera contained in 

 that cavity. They are nine pairs. Three have received the generic name of 

 psoas, and are of large volume ; they are maintained by a strong aponeurosis, 

 .the iliac fascia, and are distinguished as the great psoas, iliac psoas, and small 

 psoas. A fourth is named the square muscle of the loins (quadratus lumborum), 

 The other five, placed between the transverse processes of the lumbar vertebra, 

 represent, in consequence of their connection with these kind of fixed ribs, 

 veritable intercostal muscles ; these are the intertransverse muscles of the loins. 



Preparation. — 1. Place the subject in the first position ; open the abdominal cavity by 

 completely removing its inferior walls ; empty the cavity of the viscera it contains, and 

 excise the diaphragm, as that muscle prevents the anterior extremity of the great and 

 small psoas muscles being seen. 2. First study the iliac fascia, its form, relations with 

 the long abductor of the leg, its attachments, its continuity with the tendon of the small 

 psoas, and the expansion reflected from the aponeurosis of the great abdominal oblique 

 muscle. 3. Expose the three psoas muscles by removing the iliac fascia, the two adduc- 

 tors of the leg, and the three adductors of tlie thigh, i. Remove the psoas muscles for 

 the dissection of the quadratus and intertiansveisales. 



