188-1.] 



MR. G. E. DOBSON ON CAl'ROMYS MELANURUS. 



21J 



course, opens on its external free margin at the furthest distance from 

 the ovary ; each ovary lies close behind and external to the kidney, 

 external to which the ovarian ligament passes outwards, downwards, 

 and forwards upon the ribs and intercostal spaces, becoming lost iu 

 the peritoneal lining. 



The brachial plexus is formed from the fifth, sixth, seventh, and 

 eighth cervical, and from the first dorsal nerve, as shown iu the 

 diagram (fig. 4). Superficial branches from the seventh and eighth 



Fist. 4. 



Fig. 4. Origins and connexions of the nerves of the brachial plexus. 

 Fig. 5. Origins and connexions of the nerves of the lumbar plexus. 



a.c, Anterior crural; a.th, Anterior thoracic ; c.f, Circumflex; c.c, External cuta- 

 neous; i.c, Internal cutaneous; in, Median; m.sp, Musculo-spiral; ob, 

 Obturator; rh, Rhomboid; s, Great sciatic; sb.s, Subscapular; sp sc, 

 Suprascapular. 



nerves unite to form the internal cutaneous nerve (i.c), which is 

 distributed as usual ; and superficial branches derived from the sixth 

 and seventh nerves unite to form the musculo- cutaneous (m.c). The 

 ulnar nerve (ul) is formed by the junction of a large branch from the 

 united branches of the first dorsal and eighth cervical nerves, and 

 sends off a branch, which, with one derived from the seventh cervical, 

 forms the median nerve (m). The musculo-spiral (m.sp), a large 

 nerve, is formed under cover of the origin of the preceding nerves 

 from branches from the seventh and eighth cervical nerves, and a 

 small twig from the first dorsal. The circumflex (c.f) is formed 

 altogether from the sixth cervical, with which a communicating 

 filament is derived from the fifth nerve. 

 Proc. Zool. Soc— 1884, No. XVII. 17 



