MUSCLES OF THK TRUNK. 215 



fixed into the transverse processes of the majority of tho lumbar vertebrae, 

 uiul the inner face of the two or three lust ribs. 



Relations. I3y its up]>cr face, with the iutertransversules, the small 

 retractor of the last rib, and the fibrous fascia which unites that muscle to 

 tin- Mii:ill oblique of tho abdomen. By its inferior fuce, to the great psoas. 



Actions. It draws tho lost ribs backwards, and inclines tho lumbar spine 

 to one side. 



6. Intertransverse Muscles of the Loins. (Fig. 10 J, 2, 2.) 

 (Xi/rumym liitertraiisversales lumbar um Percivall.) 



These are very small flat muscles which fill tho intervals between tho 

 transverse processes of the lumbar vertebrae. The muscular fibres entering 

 into their composition arc mixed with tendinous fibres, and are carried from 

 the anterior border of one transverse process to the posterior border of the 

 other. 



They respond, by their superior face, to the ilio-spinalis (longissimus 

 dorsi), and by their inferior face to the quadratus, as well as the psoas 

 maguus. They act by inclining the lumbar region to one side. 



DIFFERENTIAL CHARACTERS OF THE MUSCLES OF THE SUBLUMBAR REGION IN OTHEU 

 THAN SOLU'ED ANIMALS. 



Iii Uinnintint* and the I'/;/, tho muscles of this region so closely resemble those of 

 Snli|M <!*, that a special description is unnecessary. 



In the Dog, the great psoas is little developed, and only commences at the third, or 

 i\ ii the fourth lumbar vertebra; the iliac psoas is very slender, particularly in its 

 i;il portion ; otherwise it is scarcely distinct from the great psoas, with which it mtiy 

 be said to form one muscle ; the small psoas is relatively larger than the great ; it is not 

 into the pectoral cnvity, and its anterior extremity is confounded with the 

 rum, which is longer and htronger than in all the other animals. 



COMPARISON OF THE SIBLLMBAR MUSCLES OF MAN WITH TUO.>E OF ANIMALS. 



Iii human anatomy, by the names of psoas and iliacus are described the great ptoas 

 and iliac psoas of animals. The psoas iitagnm of MAN is distinguished from that of 

 N-li|H-ds by its superior insertions, which do not go beyond tin- l.i-t dorsal vertebra*. 



The small psoas is often absent; when present, it is attached, above, to the bodies of 

 tin- twelve dorsal vertebrae, below, to the ilio-nectineal crest. 



The MwinMMMmlN have been ttudied with the muscles of the back. The 

 ijU'i'lnitH* <>f the loins, classed by anthropotomists with tin- ul>d<>minal muscles, ia 

 distinctly dividid into three s-ries of fasciculi: ilio-costal f.:>eienli, which pass from the 

 iil>l>-r border of the ilium t<i ihe twelfth rib; lumbo-costal fasiculi, (Hissing from the 

 transverse processes of the three or four last lumbar vertebrae to the twelfth rib, and //<'/ 

 litniixir fasciculi, jr..inir from tin- iliac crest to the posterior face of the transverse processes 

 of all the lumbar vertcbraj. 



COCCYOEAL I'.KOION. 



This region is composed of four pairs of muscles destined for the 

 movements of tho tail : three, named the sacro-coccyyeal, are disposed 

 longitudinally around tho coccygeal vertebrae, which they completely 

 11 \ clop ; the fourth is designated the isdiio-coccygeus. 



1. Sacro-coccygeal Muscles. (Fig. 131, 1, 2, 3.) 



These three muscles are inclosed, with those of the opposite side, in a 

 omnium ujxMieurotic sheath which is continuous with the inferior ilio sacral 

 and sjicr.i iscliiiitic ligaments. They commence on tho sacrum, are directed 

 IM< ksvards and parallel with tho coccyx, gradually diminishing in thickness, 

 jind aro decomposed into several successive fasciculi terminated by small 



