THE ORGANS OF SENSATION 



181 



'pharynx; in animals which bolt their food whole the sense 

 of taste cannot be very acute. 



Among the amphibia, the proteus, siren, pipa and xenopus 

 are tongueless ; but when the tongue exists either completely 

 attached to the floor of the mouth (salamanders), or attached 

 anteriorly and free posteriorly, as in toads and frogs, consider- 

 able importance must be attributed to it ; in fact, the tongue 

 must play a great part in tasting whenever its papillae can be 

 shown to contain nerve-endings. 



In all reptiles with horny tongues (snakes and lizards) the 

 sense of taste is to be looked for in the palate and gullet ; even 

 in the sea-turtle the tongue is small and hard though free, and 



FIG. 91. Female nosed ape. 

 (Haeckel, Anthropogenic.) 



FIG. 92. Male nosed ape. (Haeckel, 

 Anthropogenic.) 



it is only in the tortoise that it is found to be soft and covered 

 with papillae so as to be adapted to taste-perception. 



In birds a similar condition exists ; the hard horny tongue 

 of most birds does not admit of taste-perception, which is con- 

 fined to the palate and gullet. Parrots and flamingos have, 

 however, soft tongues beset with papillae differing but little 

 from the mammalian tongue ; in all cases the tongue is soft, 

 covered with mucous membrane, and except in Cetacea is well 

 provided with taste-papillae (circumvallate, fungiform and foliate, 

 p. 182). The circumvallate and foliate (marginal) papillae are 

 the commonest, the fungiform not being very widely distributed. 

 The circumvallate papillae show the highest degree of differenti- 

 ation as taste-organs (see Fig. 93), and according to Munch l 



1 A. Oppel, loc. cit., Part III., p. 194. 



