414 



MYOLOGY 



Variations. Occasionally, tendinous inscriptions occur from the tips of the tenth or eleventh 

 cartilages or even from the ninth; an additional slip to the ninth cartilage is sometimes found; 

 separation between iliac and inguinal parts may occur. 



The Cremaster (Fig. 396) is a thin muscular layer, composed of a number of 

 fasciculi which arise from the middle of the inguinal ligament where its fibers 



are continuous with those of the 

 Obliquus interims and also occasion- 

 ally with the Trans versus. It passes 

 along the lateral side of the spermatic 

 cord, descends with it through the sub- 

 cutaneous inguinal ring upon the front 

 and sides of the cord, and forms a series 

 of loops which differ in thickness and 

 length in different subjects. At the 

 upper part of the cord the loops are 

 short, but they become in succession 

 longer and longer, the longest reaching 

 down as low as the testis, where a few 

 are inserted into the tunica vaginalis. 

 These loops are united together by 

 areolar tissue, and form a thin cover- 

 ing over the cord and testis, the cremas- 

 teric fascia. The fibers ascend along 

 the medial side of the cord, and are 

 inserted by a small pointed tendon 

 into the tubercle and crest of the 

 pubis and into the front of the sheath 

 of the Rectus abdominis. 



The Transversus abdominis (Trans- 

 versalis muscle) (Fig. 397), so called 

 from the direction of its fibers, is the 

 most internal of the flat muscles of 

 'the abdomen, being placed imme- 

 diately beneath the Obliquus interims. It arises, by fleshy fibers, from the 

 lateral third of the inguinal ligament, from the anterior three-fourths of the, inner 

 lip of the iliac crest, from the inner surfaces of the cartilages of the low r er six 

 ribs, interdigitating with the diaphragm, and from the lumbodorsal fascia. 

 The muscle ends in front in a broad aponeurosis, the lower fibers of which 

 curve downward and medialward, and are inserted, together with those of the 

 Obliquus internus, into the crest of the pubis and pectineal line, forming the ingui- 

 nal aponeurotic falx. Throughout the rest of its extent the aponeurosis passes 

 horizontally to the middle line, and is inserted into the linea alba; its upper 

 three-fourths lie behind the Rectus and blend with the posterior lamella of the 

 aponeurosis of the Obliquus internus; its lower fourth is in front of the Rectus. 



Variations. It may be more or less fused with the Obliquus internus or absent. The 

 spermatic cord may pierce its lower border. Slender muscle slips from the ileopectineal line to 

 transversalis fascia, the aponeurosis of the Transversus abdominis, or the outer end of the linea 

 semicircularis and other slender slips are occasionally found. 



The inguinal aponeurotic falx (falx aponeurotica inguinalis; conjoined tendon of 

 Internal oblique and Transversalis muscle) of the Obliquus internus and Trans- 

 versus is mainly formed by the lower part of the tendon of the Transversus, and 

 is inserted into the crest of the pubis and pectineal line immediately behind 

 the subcutaneous inguinal ring, serving to protect what would otherwise be a 



Fio. 396. The Cremaster. 



