ORGAN OF TASTE IN MAMMALIA. 103 



The contrast in extensibility of tongue is very great in the 

 Lisseiicephalous group, as, e. g., between the Rodentia and 

 Bruta. Viewed as orders, the first offer the least, the latter the 

 greatest, power of protrusion and mobility of the lingual organ 

 in the whole Mammalian class : but the unimportance of this 

 character as telling against affinity is shown by a similar contrast 

 between the two representatives of the Monotreinatous order, 

 Ornithorhynchus and Echidna. The characteristics of the tongue 

 in Bruta are due to the development of its motory rather than 

 its sensory attributes, are attended with increase of the hypo- 

 glossal more than of the glossopharyngeal or trigeminal nerves, 

 and relate to the acquisition rather than to the discrimination of 

 alimentary matters. In the family (Loricata) of the order in- 

 cluding the most promiscuous feeders, the tongue is better 

 endowed with the power of testing the sapid qualities of the 

 miscellaneous oro-anic substances in the rubbish of the forests 



o 



among which the Armadillos are habitually poking their pig- 

 like snouts. Relegating, therefore, the notice of the tongue of 

 the purely phyllophagous and myrmecophagous Bruta to a 

 future chapter, I shall here merely state that, in the Armadillo, 

 the tongue tapers to the free end, has a convex dorsum, trans- 

 versely wrinkled and finely papillose : at about an inch from the 

 root, in Dasypus Peba, there are two fossulate papillae l on the 

 same transverse line, behind which a medial furrow extends to 

 the epiglottis. 



The tongue has but little mobility and a small extent of free 

 margin in any Cetacean. In the Porpoise the tip is fringed by 

 obtuse processes of varying length, but all short, fig. 296, h, the 

 dorsum is flat, devoid of papillous processes, and smoothly covered 

 by a level of thick epithelium. In the Grampus a similar fringe 

 extends some way back on each lateral margin of the tongue. 

 Anteriorly these margins are made irregular, in the Cachalots, 

 by fissures and warty prominences. The Whales have not the 

 fringed or verrucose marginal structure. The tongue in them is 

 chiefly remarkable for its huge size even relatively to the body ; 

 and this is mainly in breadth and depth. When swollen by 

 putrefaction the fore part may be protruded a little way as in 

 fig. 217. The dorsum, devoid of papillae, has its membrane thrown 



1 Daubenton states that he saw not any papillae even with a strong magnifier, cxxn', 

 vol. x. p. 242 ; and De Blainvillc appears to have been led by this statement to affirm 

 of the ' glands calycinales des Edentes,' that ' quelquefois dies sont nulles,' LXXX", 

 p. 255, of which, however, I have seen no instance. 



VOL. III. O 



