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H. W. NORMS AND SALLY P. HUGHES 



around the anterior border of this nerve, turns laterally into the 

 orbit, and divides into two branches, one of which immediately 

 enters the anterodorsal part of the rectus lateralis muscle, the 

 other the anteroventral part (figs. 10, 11, 15 to 17, and 20). 



Fig. 18 A horizontal section through the trochlear decussation, showing the 

 relations of the trochlear roots and the radix mesencephalica V. Section cut 

 somewhat obliquely. X25. 



Fig. 19 A horizontal section through the trochlear nidulus, showing the rela- 

 tions of the trochlear root and the radix mesencephalica V. X25. 



