MAMMALIA. 673 



In botli these animals the tongue suddenly becomes much con- 

 tracted at the place where it begins to be free from the surround- 

 ing parts. It then appears to be made up of two very long and 

 slender muscular cones, laid one upon the back of the other, their 

 apices being at the end of the tongue.* Each of these cones 

 consists of two muscles: one external, composed of a multitude of 

 distinct fasciculi investing the internal muscle in a circular manner, 

 and forming around it numerous little rings resembling the annelli 

 of an earth-worm. The internal muscle, on the contrary, is of 

 great length ; it arises from the middle and upper part of the 

 sternum, runs forward along the neck, passes between two layers 

 of the mylo-glossus, and afterwards becomes surrounded by the 

 annular muscle. It is composed of distinct fasciculi, rolled upon 

 themselves in an elongated spiral ; the external fibres terminate at 

 the first rings, those beneath attain the rings that succeed, and so 

 on until the innermost fibres reach quite to the extremity of the 

 tongue. It is easy to perceive that, by its action, this muscle 

 will shorten the tongue until it lies in a very small compass, or 

 bend it in any direction ; whilst the annular muscle will lengthen 

 it, exactly in the same way as the body of a leech is extended or 

 contracted. 



In the Ant-eater the annular muscle does not appear so dis- 

 tinctly double as it does in the Echidna; but it forms by itself 

 almost all the substance of the tongue, which is thus capable of 

 being elongated to a wonderful extent. 



(752.) Regarding the tongue with reference to the sense of 

 taste, the Mammalia may be looked upon as the only animals 

 capable of receiving much enjoyment from this source, since in 

 them alone the lingual mucous lining seems to be perfectly 

 adapted to gustation. Even among these highly endowed crea- 

 tures, it is only in Man, and those Herbivorous orders that pre- 

 pare their food in the mouth by a prolonged mastication, that 

 the sense in question exhibits much delicacy of perception ; for 

 the Carnivorous quadrupeds, seeing that they tear to pieces and 

 swallow their food in large morsels, can scarcely be supposed to 

 pay much attention to its sapid qualities. 



In the Cat tribe (Felida), indeed, all the middle portion of the 

 surface of tongue is covered over with sharp, recurved, and horny 

 spines, adapted as it were to file off remnants of soft flesh from the 



* Cuv. Le9ons d'Anat. Comp. torn. iii. p. 264. 



