8 ABDOMEN. 



ilii, the fibres arise from a tendinous lamella, insertion of the tendon of the transversalis 

 which itself is trifoliate in its origin. This ten- muscle; but Mr. Guthrie has lately called the 

 don is found as an undivided lamella between attention of anatomists to a variety which it 

 the outer margin of the quadratus lamborum and is important to know, although it cannot be 

 the commencement of the fleshy fibres of the of frequent occurrence. In this variety the 

 muscle, extending vertically from the last rib spermatic cord appears to pass through a slit in 

 to the crista ilii. (Fig. 4, 1.) The three laminae the inferior margin of the transversalis muscle, 

 of which this tendon is composed arise from so that a bundle of muscle passes behind as 

 different portions of the vertebrae in the lumbar well as before the cord ; the posterior one end- 

 region of the spine ; the posterior, which is ing in tendinous fibres, which, like the folded 

 thick and strong, and is commonly called fibres above described, are inserted into Pou- 

 J'uscia lumborum, arises from the extremities part's ligament.* It is very generally believed 

 of the spinous processes, and covers the lum- that the inferior fibres of this muscle contribute, 

 bar mass of muscles. (Fig.4,g.) The mid- as well as those of the obliquus internus, to 

 die, which is weak, is attached to the apices of form the cremaster. The two muscles are so 

 the transverse processes ; it lies in front of the closely connected externally by their inferior 

 ' lumbar mass and behind the quadratus lumbo- margins, that it is natural to suppose that both 

 rum (Jig. 4, h); and the anterior arises from the do send fibres to the cremaster. Sir Astley 

 pedicles which connect the transverse processes Cooper expresses the relation of the cremaster 

 to the bodies of the vertebras, and covers the to these two muscles in the clearest way, when 

 quadratus lumborum muscle in front (Jig. 4, he says that it arises from Poupart's ligament 

 j). Inferiorly, the transversalis muscle at- within the inguinal canal, and there blends with 

 taches itself to the inner lip of the crista ilii some of the fibres of both these muscles.f 

 for its three anterior fourths, and to the ex- A thin layer of cellular tissue covers the 

 ternal third or half of Poupart's ligament, cor- transversalis muscle, and separates it from the 

 responding to the attachments of the obliquus obliquus internus. At its superior margin it 

 internus. The fleshy fibres of the muscle pass is intimately related to the diaphragm, and 

 from these several points of attachment trans- some of its fibres seem to be continuous with 

 versely inwards, the middle being the longest, it : posteriorly, by the triple partition of its 

 and the superior the shortest, and are in- tendon, it ensheaths the lumbar muscles, and it 

 serted into the outer convex margin* of a lies upon the fascia transversalis, which, with a 

 tendinous aponeurosis, which extends to the layer of cellular tissue, separates it from the 

 linea alba. This aponeurosis is intimately peritoneum. J 



connected with the posterior division of that 4, Rectus abdominis (sterno-pubien). After 

 of the obliquus internus for an extent corre- the superficial fascia has been removed so as 

 spending to the three superior fourths of to expose the aponeurosis of the external ob- 

 the rectus muscle, behind which both pass to lique, the recti muscles are seen on either side 

 be inserted into the ensiform cartilage and of the middle line covered by this aponeurosis, 

 linea alba, (fig. 4, a,) forming the posterior which it is necessary to slit up in order to ex- 

 wall of the sheath of the rectus. Inferiorly, as pose the muscles. The rectus owes its name 

 we have already remarked, these conjoined to the perpendicular course of its fibres, which 

 tendons go together in front of the rectus, and pass from the pubis to the thorax, nearly 

 are inserted into the inferior fourth of the linea parallel to the middle line. It is long and 

 alba and into the pubis. At the inner extre- narrow ; however, its breadth increases as it 

 mity of the inguinal canal, it will be seen by advances upwards, and as it increases in breadth 

 carefully raising up the spermatic cord, that it diminishes in thickness. At the pubis the 

 this union of the tendons of these two muscles muscle has its most fixed point of attachment, 

 ceases, and we can trace the fibres of the trans- whence it is generally said to have its origin 

 versalis tendon passing down in a curved direc- there : it arises by a short tendon from the 

 tion, more curved as they are more external, symphysis of the pubis; this tendon is very 

 and insinuating themselves behind the cord to narrow at its origin, but soon expands, and 

 be inserted into Gimbernat's and Poupart's unites with the muscular fibres, which pass 

 ligament for about its external third or fourth, vertically upwards to the lower margin of 

 This mode of insertion of the transversalis ten- the thorax, where the muscle is considerably 

 don was first described by Sir Astley Cooper, f increased in breadth, and divides into three 

 and these fibres were by him called the folded portions ; the first or internal one is inserted 

 fibres of the transversalis. They adhere to the into the costoxiphoid ligament and cartilage 

 subjacent fascia, (fascia transversalis,) and add of the seventh rib ; the middle, larger than 

 to the strength of the inner portion of the pos- the preceding, into the cartilage of the sixth 

 terior wall of the inguinal canal. They cor- rib at its inferior edge and anterior surface; 

 respond, in a great measure, to the external 



abdominal ring, and may be counted as one of * r , f u r - , v 



t L.- _i j j * . Uuthne on Inguinal and Femoral Hernia, pp. 



.he obstacles provided against the direct descent n, 12, 13, 4 to . Lond. 1833 



of a hernia. t Op. cit. p.* 38. 



Such is unquestionably the usual mode of t " The transversalis corresponds, by the direction 



of its fibres, to the ' triangularis sterni ;' also, by its 



9 ,, . , situation, by the attachment of its external edge to 



margin forms the linea semilunaris of the internal surface of the ribs, and by that of its 



Spigelms. internal edge to the sternum and linea alba." 



t Cooper on the Testicle, p. 35. Meckel. 



