108 ON THE VAGUS NERVES OF TIJE EDENTATA. 



the ventral wall of the stomach. The right vagus i-uns along the 

 lesser curvature of the stomach to the pyloric region. Both vagi 

 send branches to the oesophagus. 



The Gmliac Plexii^s resembles that in Eupliractus in most 

 points. 



Summary and Conclusions. 



1. The course of the vagus nerves resembles that in the 

 Marsupialia, but their thoracic relations are similar to those in 

 Man. 



2. The superior cervical sympathetic ganglia are present in the 

 neck iu Euphractihs aiid Tatusia, but are represented by wide 

 expansions within the foramen lacerum posticum in Tamandua. 



3. In Tamandua the pharyngeal plexus is more complicated 

 than that in Eujihractus or Tatusia^ and it is the only species in 

 which the lingual branch of the vagus is present. 



4. In Eujihractus the nerves accompanying the branches of the 

 common carotid artery are larger and more numerous than in the 

 other genera. 



5. No Edentate examined by me has a middle cervical sympa- 

 thetic ganglion, and the thoracic ganglia are few in number. 



6. The cardiac plexuses are built on the same plan, but there 

 are variations in detail in their communications and ganglia in 

 the various species. 



7. Each species exhibits a diflerent ari'angement of the vagi in 

 the posterior part of the thorax, and their intercon.munications 

 are variable. 



8. The solar plexus in Tamandua differs in its arrangements 

 and distribution from that in Euphractus and Tatusia. It does 

 not lie aci"Oss the vertebral colinun, but is situated within the 

 mesentery along the course of the coeliac axis. 



9. The splanchnic nerves are well-developed in all species, but 

 do not all arise from ganglia. 



10. There is no separate depressor nerve, and no external 

 communication between the superior and recurient laryngeal 

 nerves as in Hyrax capensis and Man. 



Bibliography. 



1. SoNNTAG, C. F. — Proc. Zool. Soc. London. 1921, pp. 572-575. 



2. SoNNTAG, C. F.— Proc. Zool. Soc. London, 1921, pp. 873-876. 



3. Ou-NNiNGHAM, D. J. — Text-book of Anatomy, p. 655. 



