OF THE TONGUES OF THE MAMMALIA. 17 



in the other Anthropoids, but simply a fold over Wharton's 

 Ducts. 



The tongue of the Orang-Outan, therefore, resembles that of 

 Man in the following particulars: — 



1. Its general proportions. 



2. Its rounded apex. 



3. The V-type of vallate papillae. 



4. The absence of long conical papillfe on the base. 



5. The frenum lingua\ 



6. The small proportions of the fimbriate plicae. 



7. The nature of the sublingual fold. 



8. It has an Apical Gland of Niihn or Blandin. 



In all these particulai-s it diffeis from the Chimpanzee and 

 Gorilla, so it must be placed next to that of Man in a classifica- 

 tion of tongues. 



Symphatangus. 



The Siamang (S. syndactylm). 



(Specimen No. J. 357.3, Mus. R.C.S.) 



The tongue is long and narrow, and the distance between the 

 antero-median ^•allate papilla and the epiglottis is long (text- 

 fig. 5). 



The cqjex is rounded and devoid of a notch. It beai-s conical 

 and fungiform papilhe which have the usual disposition. 



The lateral borders are full and rounded. They bear conical 

 papillae with backwa.rdly-directed points, prominent fungiform 

 papillae, and the chief parts of the lateral organs. This condition 

 is present in all Gibbons, but the fungiform papillse vary in size 

 and prominence in difterent species. 



Mesial and transverse sulci are absent on the anterioi- two- 

 thirds of the dorsum. Both are present on the base of the 

 tongue, but these may have been induced by the preserving fluid. 



The mesial ventral sulcus begins at the posterior border of the 

 papillary zone, and runs backwai'ds to open into a triangular 

 depression into which the frenum passes. 



The Papillae. 



Papillae are present on the apex, lateral borders, the entire 

 anterior two-thirds of the dorsum, the sides of the posterior 

 third of the dorsum, and the bounding zone on the inferior 

 surface. 



On the posterior third of the dorsum there is a large central 

 area devoid of papillae (text-fig. 5). It stretches forwards 

 anterior to the median row of vallate papilke, and sends out 

 limbs on which the lateral papillse stand. It extends right back 

 to the epiglottis, and is ridged and furrowed at its posterior part. 

 Antei'iorly it is bounded by small conical papillee, and large 



Piioc. ZooL. Soc— 1921, No. II. 2 



