OF THE TONGUES OF THE MAMMALIA. / 65 



organs are better develoj^ed, and the conical papiilse on the oral 

 part of the dorsum include more pointed forms, but Homo alone 

 of all tlie Primates possesses a foramen Cfecum. 



The ladder-like patterns formed by the Lateral organs distin- 

 guish Simla satyo'us and Gorilla gorilla from all other Simiidaj 

 which have organs convex towax'ds the lateral vallate papilla;, but 

 the tongue of Gorilla gorilla has enormous conical papillae on the 

 pharyngeal part of the tongue, large plicfe fimbriate, a median 

 ventral crest, and a large triangular frenal lamella ; it has no 

 Apical Gland of Nuhn, and its vallate papillae foi-m a Y or Y. 



The only character which really differentiates Anthrojjoplthecus 

 troglodytes on the one hand from Hijlobates and SympJiatangus on 

 the other is the possession of plicae fimbriatse, for there is a 

 similarity between them in all othei- features ; and Hylobates has 

 a well-marked, triangular, bifid lamella, whereas Sympliatangus 

 syndactylus has two small folds over Wharton's Ducts similar to 

 those of Homo and Simia satyrus. Their vallate papillte form 

 a Y. 



In the Cercopithecidse, Cehida>, and Hapalidas the vallate 

 papillae never form a Y, the conical papillae on the base of the 

 tongue are never disproportionately large, and the lateral organs 

 are neither ladder-like nor convex towards the lateral vallate 

 papillae. The chief differences between them lie in the characters 

 of the lateral organs, the size of the apical cluster of fungiform 

 pa.pilhe, and the mode of arrangement of the conical papillae on 

 the oral part of the dorsum. 



In the Cercopithecidae the lateral organs form rows of laminae 

 and sulci on the lateral borders, the apical cluster of fungiform 

 papilhie is large, and the conical papilhe on the oral part of the 

 dorsum are regularly arranged. The genera are distinguished by 

 the characters of the orifices of ducts and pits on the pharyngeal 

 part of the dorsum (page 762). 



In the Cebidae the inner borders of the lateral organs are con- 

 cave towards the lateral vallate papillae, the conical papillae on 

 the oral part of the dorsum are crowded together without any 

 definite arrangement, and the apical cluster of fungiform papillae 

 is small. 



The vallate papillae are two in number, and there is a well- 

 marked median sulcus on the pharyngeal part of the dorsum in 

 Aotus, but in all other genera there are more than two vallate 

 papillae, but no basal dorsal sulcus. 



The ventral papillary zone is wide, aiid has few fungiform 

 papillae in Lagothrix^ but it has many papilla? in Ateles and Cebus. 

 In Ateles the ventral fungiform papillae are most niunerous 

 round the apex, but in Cebus they are most numerous farther 

 back. 



The ventral papillary zone is narrow in Pithecia, Alouatta, 

 Callicebus, and Gacajao. It has many fungiform papillae in 

 Pithecia but few or none in the others ; and Alouatta is the only 



