138 The Alligator and Its Allies 
agus, and trachea; (3) goes to the cesophagus; (4) 
goes to the heart, lungs, and stomach. 
XI. The spinal accessory nerve. There seems 
to be some doubt as to the exact identity and 
distribution of this nerve, but Bronn says that, 
according to Fischer, it gives twigs to the lower 
head-muscles and then divides into fine branches 
in the atlanti-mastoideus muscle. 
XII. The hypoglossal nerve, going to the region 
of the tongue, divides into three branches: (1) the 
median and smallest goes to the sterno-maxillary 
muscle; (2) the inner and larger goes to the same 
muscle and also to the coraco-hyoid and sterno- 
hyoid muscles; (3) the outer and largest divides in- 
to three twigs of which the first two lead to the 
hyomaxillary and sterno-maxillary muscles respec- 
tively, while the third divides into two twigs that 
lead to the hyoglossal and genioglossal muscles 
respectively. 
THE SPINAL NERVES 
As was noted above, the dorsal roots of the first 
two spinal nerves are lacking. 
I, II, and III. The ventral branches of these 
three nerves supply the smaller, ventral neck 
muscles. 
IV. The ventral branch of this nerve innervates 
with its chief divisions the ventral muscles, the 
sphincter colli, and the integument of the neck, 
