1887.J 



ANATOMY OF HYDROMYS. 



59 



off the greater portion of the anterior thoracic nerve. The 6th nerve 

 divides into two portions, an upper and lower. The combined cord 



formed by the 



/th cervical and 

 Fig. 



1st dorsal also divides into tvfo 

 1. 



M.S. 



Cervical and brachial nerves. (Diagrammatic.) 



1-7. Cervical nerves; I.D. 1st dorsal nerve; Sp.Sc. Suprascapular ; Sb.Sc. Sub- 

 scapular ; Cflx. Circumflex; 3/. C. Musculo-cutaneous ; Tr. Nerve to tri- 

 ceps; M.Sp. Musculo-spiral ; U. Ulnar; 31. Median; Cu. Internal cuta- 

 neous ; Phr. Phrenic ; Th. Anterior thoracic ; M.M. Muscular branches. 



portions, an anterior and a posterior. The upper part of the sixth, 

 having received the branch from the circumriex, joins the anterior 

 part of 7+1, and the combined trunk becomes musculo-spiral, having 

 previously given off branches to the tricep.s and other muscles. The 

 lower division of 6 joins the posterior of 7+ 1> having first given off 

 a filament which joins the anterior thoracic. The large trunk thus 

 formed, having given off some muscular branches, splits up into ulnar, 

 median, and internal cutaneous. 



Lumbosacral Nerves (fig. 2). — The 1st lumbar forms the iho- 

 hypogastric and the 2nd the ilio-inguinal. These nerves are 

 connected with one another by a communicating branch, but have no 

 junction with those below. The 3rd gives off genito-crural, a 

 branch of communication with 4, and in conjunction with a branch 

 from this last forms external cutaneous. The remaining portion of 

 4 with a branch from 5 forms a common trunk which divides into 

 obturator and anterior crural. The great sciatic is formed by the 



