OF THE TONGUES OP THE MAMMALIA. 521 



large as in many Carnivora. I was unable to cut into the 

 tongues of Manis, Myrmecophaga or Orycteropus, but I found no 

 trace of it in Taniandua, Braclypus, Dasypus or Tatusia. 



The frenum is short in all Edentates. 



There is no trace of plicae fimbriata^ or f'renal lamellae. The 

 musculature and elastic tissue have already been fully described 

 by Owen (18) and others. No intermolar eminence is present. 



Sir William Flower (27) came to the following conclusions as 

 regards the affinities of the Edentates; — "All the American 

 Edentates at present known, however diversified in form and 

 habits, belong to a common stock. The Bradypodidce, Mega- 

 theriidce, and Myrmecophagidce are closely allied, the modifications 

 seen in existing families relating to food and manner of life. 

 The ancestral forms may have been omnivorous, like the present 

 Armadillos, and gradually separated into the purely vegetable 

 and purely animal feeders; from the former are developed the 

 modern Sloths, from the latter, the Anteaters. The Armadillos 

 are another modification of the same type, retaining some more 

 generalised features, as those of the alimentary organs, but in other 

 respects, as their defensive armature, remarkably specialised. 



" The two Old-World forms Manidce and Orycteropidce are so 

 essentially distinct from all the American families, that it may 

 even be considered doubtful whether they are derived from the 

 same primary branch of mammals, or whether they may not be 

 offsets from some other branch, the remaining members of which 

 have been lost to knowledge." 



It was shown above that the tongues of the American 

 Edentates have two circumvallate papillas, whereas those of the 

 Old-World forms have three ; and it is only in rare specimens 

 that this arrangement is departed from. 



If the Armadillos were like the ancestral forms, as Flower 

 believed them to be, it is necessary to see whether their tongues 

 could have been transformed into those of the Myrmecophagidse 

 and Bi-adypodidse. The tongue of any Armadillo is long and 

 triangular, with a slightly bulbous apex and a good supply of 

 fungiform and conical papillae ; and in some species there are 

 lateral organs. If the tongue be simply shortened, with loss by 

 absorption of the apical swelling, it would become indistinguish- 

 able from that of JBradypus. Conversely, enormous elongation 

 of the tongue, with retention and specialisation of the apical 

 swelling, produces a tongue like that of Tamandua or Myrmeco- 

 phaga ; and as the tongue in these insectivorous animals is merely 

 a glutinous finger, the conical and fungiform papillae on the 

 dorsum would undergo disuse atrophy. So it is evident that the 

 mere changes in form, with or without disuse atrophy, would 

 convert the tongue of an Armadillo into that of a Sloth or an 

 Anteater. 



The tongue of Manis resembles those of the Myrmecophagidse 

 in its general form, and in the specialisation of the apex to form 

 a sensory organ ; but the likeness between them stops there. 



