THE TEETH OF EDENTATA. 305 



of the great sub-maxillary glands, and is wielded with 

 much dexterity. The Manis, or Scaly Ant-eater is also 

 edentulous. 



The Edentata belong to the monophyodont or homodont 

 section of Mammalia ; but, in some, certain teeth are more 

 largely developed than others, so that we have teeth which 

 might be termed canines ; and it has already been mentioned, 

 that one armadillo, at all events, is diphyodont. 



The teeth are of simple form, and do not in any marked 

 degree differ in the different parts of the mouth, except 

 only by their size (to this the canine-like tooth of the two- 

 toed sloth is an exception). They are all of persistent 

 growth, and therefore no division of parts into crown, neck, 

 arid root is possible : they consist generally of dentine and 

 cement, with sometimes the addition of vaso-dentine, into 

 which latter tissue the central axis of the pulp is converted ; 

 while in some members of the order other peculiarities of 

 structure exist : thus in the Orycteropus (Cape Ant-eater), 

 dentine like that of Myliobates is found ; and in the Megathe- 

 rium hard dentine, a peculiar vaso-dentine, and richly 

 vascular cementum co-exist (see Fig. 43). 



I am not aware that enamel has been seen upon the teeth 

 of any Edentate animal, but I found some years ago that 

 the tooth germs of the nine-banded armadillo were provided 

 with enamel organs ; this, however, proves nothing, for 

 (Philos. Trans., 1876) I believe the presence of enamel 

 organs to be universal and quite independent of any after 

 formation of enamel. 



The teeth of the nine-banded armadillo (T. peba), will 

 serve to illustrate the character of the dentition of the 

 class. They are seven in number on each side of the jaw, of 

 roundish form on section, and those of the upper and lower 

 jaws alternate, so that by wear they come to terminate in 

 wedge-shaped grinding surfaces : before they are at all 



