VISCERAL RAMI OF THE VAGUS. I09 



The motor fibres for the last two muscles leave the 

 oesophageal complex near the point v^here the fourth 

 branchial trunk separates, encircle the oesophagus, then 

 divide and enter their respective muscles from behind and 

 can easily be traced to their ultimate ramifications within 

 these muscles. 



This account confirms the general statement of Stan- 

 nius ('49, p. 90). Wright ('84, p. 371) states that the 

 pharyngo-claviculares are supplied by the first spinal 

 nerve in Amiurus, and Harrison ('95) makes the same 

 statement for Salmo. Vetter ('78, p. 524) states that they 

 are supplied by the vagus in Esox ; in Perca he demon- 

 strated the innervation of the internal muscle from the 

 vagus, but in Cyprinus he found that the ventral nerve 

 formed from the first two spinal nerves (XII nerve of 

 authors, r. cervicalis of Fiirbringer) runs along the hinder 

 edge of the m. pharyngo-clavicularis internus and he 

 thought that the hinder part of this muscle receives some 

 fibres from that source. In selachians and chimseroids these 

 muscles are supplied by the spinals (Fiirbringer, '97). In 

 Amia (AUis, '97, p. 697) they are supplied from the vagus 

 essentially as in Menidia, though in that case their nerve 

 runs out with the ramus post-trematicus n. vagi quarti. 

 Allis corrects McMurrich's statement ('85, p. 138) that the 

 claviculares in Amia are supplied by the first spinal. The 

 nerve (which really is the fourth spino-occipital nerve) 

 merely traverses the muscle. 



Fiirbringer ('97, p. 469) describes the external and in- 

 ternal pharyngo-claviculares (his cleido-branchialis 5, 

 external and internal) as innervated from the spinal 

 nerves in Esox, Gadus and Caranax, and he considers that 

 Stannius and Vetter are in error when they describe them 

 as supplied by the vagus. In this it would appear as if 

 Fiirbringer were unduly influenced by theoretical con- 

 siderations. Regarding the cleido-branchiales as somatic 

 muscles, it accords ill with his scheme of somatic and 

 visceral nerves to find these muscles innervated from the 



