CoGHiLL, Cranial Nerves of Amblystovia. 289 



X. /. — lateralis root of vagus. 



X. 2, J, 4. — second, third and fourth roots respectively of the vagus. 



X. 4. a, />, c, d. — rootlets of the fourth root of vagus which are variable. 



X. ibr.— first truncus branchialis vagi. 



X. 2br. — second truncus branchialis vagi. 



X. ii>r. I, ^, 6, J, S,g, 10. — first, fifth, sixth, seventh, eighth, ninth and 

 tenth branches of first t. branchialis vagi. 



X. 2br. J, 4, S, 7, cS'. — third, fourth, fifth, seventh and eighth branches re- 

 spectively of the second t. branchialis vagi. 



PLATE XV. 



Fig. T. A projection of the roots and ganglia of the fifth, seventh, ninth, 

 tenth and first two spinal nerve of Amblystoma upon the horizontal plane. 

 This projection is made to scale from serial sections of the head. 



PLATE XVL 



Fig. 2. A projection of the cranial nerves of Amblystoma on the sagittal 

 plane. This projection is made to scale from serial sections of the head. In 

 the figure as it is here presented it has been necessary to modify the position 

 of some nerves in order not to obscure others. The trunk of the glossopharyn- 

 geus as it passes backward and downward is pushed downward from its actual 

 position in order to bring the t. visceralis into view. The order of branching of 

 the fifth, sixth and seventh branches of the first branchial X trunk has been 

 changed for sake of clearness in their peripheral relations. The actual course of 

 Isd, also, is modified in relation to other nerves. These, and other slight altera- 

 tions in the relative position of nerves, do not change the essential relations of 

 the components which it is the prims; purpose of the projection to show. 



