ON THE ANATOMY OF THE TONGUES OF THE MAMMALIA. 



115 



10. The CoHiparative Anatomy of the Tongues of the 

 Mammalia. — I. General Description of the Ton o ne. 

 By 0. F. SoNNTAG, M.D., Ch.B., F.Z.S., Anatomist to 

 the Society. 



[Received January 22, 1920 : Read March 16, 1920.] 

 (Text-figm-es 6-17.) 



A coosiderable body of Kterature dealing witli tlie development 

 and histology of the tongue has appeared in recent years, and a 

 number of individual tongues and groups hnve been described. 

 No one has, however, taken the various striictnres and shown 

 how tliey vary in different animals in exactly the same manner as 

 I have described here. It is the object of my series of papers to 

 fill this gap, and show how the tongue is of value for purposes 

 of classification. In this paper I have indicated the different 

 directions in wliich the various structuies can be modified, and I 

 liave defined the terms used in the sncceediug ones. 



The tongue is a muscular organ enveloped in mucous membrane 

 except at the base and the posterior pait of the inferior surface 

 where the muscles, nerves, vessels, and lymphatics enter and 

 leave it. On the dorsum and inferior surface tlie mucosa differs, 

 being firmly adherent in tlie former situation and loosely 

 attached to the subjacent tissues in the latter. On the dorsum, 

 lateral border, and, in most cases, on a bounding zone of the 

 inferior surface it is covered with innumerable papillic which 

 make these parts rough to the touch. The roughness reaches its 

 greatest degree of development in the Felidse, in which the 

 individual papill?e stick into the finger like so many pins. In 

 the non-papillary part of the inferior surface, the mucosa is 

 smooth, but it may have ridges and fissures. These do not, 

 however, affect the smoothness. 



Shape. 



Mammalian tongues differ greatly in shape, being oval, conical, 

 spatulate, trianguhir, or vermiform, but these forms are not of 

 any value for comparative purposes. 



Size. 



Two sets of measurements must be made — tlie greatest width, 

 and the length — and the latter is divided into two the lengths 

 of the oral and pharyngeal parts, in most cases the greatest 

 width is situated at the attachments of the anterior faucial 

 pillars to the doreum, but in spatulate tongues it may lie farther 

 forwards. 



The length is measured from the apex to the mid point of the 

 glosso-epiglottidean fold. The oral part extends from the apex 

 to the median circumvallate papilla, when there is one, or to 



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