l8o 'Journal of Comparative Neurology and Psychology. 



branch, which is beginning to divide into the inferior alveolar 

 and the lingual nerves. 



The intermedius joins the facial portion and divides into a supra- 

 branchial branch (large superficial petrosal nerve) and a post- 

 branchial branch. The latter forks to form the chorda tympani 

 in front and the facial nerve behind. Although the petrosal nerve 

 and chorda tympani are predominantly sensory and the facial 

 nerve is chiefly motor, Weigner^ has shown that all three 

 branches contain some fibers of both sorts. 



The glossopharyngeus has a suprabranchial branch (tympanic 

 nerve) and a postbranchial branch which divides to form the 

 lingual ramus in front and the pharyngeal ramus behind. The 

 tympanic nerve and the lingual ramus are chiefly sensory and the 

 pharyngeal ramus is mixed. 



Neither the intermedius nor the glossophary-ngeus possesses in 

 mammals a praebranchial branch, but both of them have sub- 

 branchial branches which have not been described in fishes. 

 These are the chorda tympani and the lingual ramus respectively. 



The vagus has neither a suprabranchial nor a praebranchial 

 branch in relation with the third cleft. The postbranchial nerve 

 for this cleft has been identified by Froriep as the superior 

 laryngeal nerve. In the pig of 12 mm. there is a small plexus 

 between the third and fourth pouches, in which a praebranchial 

 branch for the fourth pouch may be represented. There is no 

 nerve passing between the fourth pouch and the postbranchial 

 body, which by some authorities is counted a fifth pouch, although 

 a small nerve runs beside the postbranchial body. This may be 

 what Froriep (loc. cit., p. 16) described as a postbranchial 

 branch for the fourth pouch. In cow embryos it was a small 

 nerve which disappeared in later stages. Behind the post- 

 branchial body and the pulmonary aortic arch, the vagus sends 

 out the recurrent nerve, a large branch which may represent a 

 fusion of nerves for pharyngeal pouches which fail to develop. 



The course of the ramus externus, which contains accessoria 

 fibers for the trapezius and sternomastoid muscles has not been 

 satisfactorily explained. 



The sensory portions of the intermedius, glossopharyngeus and 

 •vagus thus far described supply the splanchnic structures only. 



i\Veign'er, K., Anat. Hefte, 1905, Vol. 29, pp. 97-162. 



