THE LYMPHATIC SYSTEM. 



253 



angles of the maxillary septum. At the root of the anterior ex- 

 tremity it divides to enclose the root of the limb, and so form the 

 axillary septum, 



(3) The pectoral septum {Seiitum pectorale), (Figs, 170 and 17 17-*) 

 is attached to the superficial surface of the M. pectoralis [Porfio 

 sternalis, anterior and posterior) ; it runs transversely across the body, 

 and is attached at its outer end to the ventral and to the maxillary 

 septa. The septum passes obliquely backwards and downwards 

 to be attached to the skin, and so forms a very acute angle with 

 the M. cutaneus pectoris {cjj) : a vertical band of connective-tissue, 

 broad behind, narrow in front, extends in the middle line from the 

 septum to the body wall ; from it a certain amovmt of loose con- 

 nective-tissue extends in all directions, and forms open lymph-spaces 

 between the MM. cidanei pectorales and the vertical septum. 



Fiff. 168. 



(4) The perineal septum {Bepdnm 

 perineale), (Fig. lyope). This me- 

 dian septum extends from the at- 

 tachment of the dorsal septum to the 

 tip of the urostyle, backwards to the 

 symphysis pubis, where it joins the 

 ventral septa. In its attachment 

 it follows the middle line of the 

 perineum. 



(5) The maxillary septum (Sep- 

 tum maxillare), (Figs. 170, lyi/j/) 

 is attached by either extremity 

 to the dorsal septum, near the 

 tympanic membrane, is continued 

 downwards to unite with the 



anterior end of the ventral septum, and then runs across the 

 anterior pectoral region, forming a curve with the convexity 

 forwards. It has inserted into it fibres of the 31. suhmaxillaris. 

 The septum is formed of very loose tissue, and frequently contains 

 deposits of fat; it encloses a well-marked septal sinus, the Sinus 

 thoracicus transversus (Ecker). 



(6) The iliac septum (Figs. 169, 172 15, 173 S') is a septum 

 extending from the dorsal septum to the inguinal septum. It is 

 attached to the dorsal septum opposite the anterior end of the 

 M. glutaens, and extends outwards and downwards to the inguinal 



Sinus thoracicus transversus (Ecker). 



cp M. cutaneus pectoralis. 

 // Skin reflected forwards. 

 .V Sinus witli its afferent vessels. 



