176 COMPARATIVE MORPHOLOGY OF VERTEBRATES. 
the medulla to the ganglion jugularis, beyond which the dorsal rami 
arise and then the main trunk runs backward, giving off as many 
branchial nerves as’ there are gill clefts, each with an epibranchial 
ganglion and each dividing into pre- and post-trematic rami. To 
this extent the tenth is a polymeric nerve with coalesced proximal 
portions. 
Near the last cleft the main trunk divides into two nerves. One of 
these, the ramus lateralis, continues back, just beneath the skin, to 
innervate the lateral line organs of the trunk and tail. The other, the 
Fic. 174.—Diagram of cranial nerves of a cat, the lower jaw reflected, after Mivart. 
II~XII, cranial nerves; ct, chorda tympani; d, dentary nerve; g, Gasserian ganglion; 7a, 
infraorbital nerve; /, lingual nerve; /z, /s, laryngeus inferior and superior; md, mandibularis 
nerve; mx, maxillaris nerve; 0, ophthalmic nerve; ¢, tongue. 
ramus intestinalis, goes inward and backward to supply the cesoph- 
agus, stomach, heart and other viscera (in air-breathing vertebrates the 
lungs also, whence the name pneumogastric nerve). In the dorsal 
rami and the branchial nerves the components are about the same as in 
the ninth nerve. The most caudal of the motor roots of the vagus 
furnish visceral motor fibres which go to some of the muscles connected 
with the pectoral arch and appendages, while others pass, by way of the 
intestinalis, to the viscera. In the same way visceral sensory fibres go 
through the same nerve to the taste buds of the pharynx, and in the 
