Marsupialia — Wombats, etc. 



75 



forth in a blind and very imperfect condition ; and, in those Marsupi- 

 forms in which that organ is present, are then placed by the alia, 

 parent within a fold of the integnment, which forms the " pouch " Wall-case, 

 or marsupium, whence the order derives its name. Within this *' 



pouch the mammary glands are situated, and to the prominent TaTole-cases , 

 nipple the young one at once becomes firmly attached and 15. 

 remains so for some time after birth. In other cases, as among 

 some Opossums, the young are carried on the back of the mother, 

 on which they are supported by twisting their tails round that 

 of the mother. The posterior angle of the lower jaw is generally 

 bent inwards (see Fig. 89, showing inflexion). There are 



t ig. S9. — Posterior view of the lower jaw of the Wombat, Pliascolomi/s. 



Fig. 90. — Dentition of Hi/pstprymnvs. i 1 to 3, three upper incisors ; i, lower incisor ; 

 •■. canine ; pm, last upper and lower premolar ; m 1 to 4, upper and lower molars. 



always true teeth implanted in the usual manner in both jaws, 

 and divisible into incisors, canines, premolars, and molars, but 

 they vary much in the different families (see Figs. 90 

 and 93). 



There is no vertical displacement and succession of the teeth, 

 except in the case of a single tooth on either side of each jaw, 

 which is always the hindmost of the premolar series, and is pre- 

 ceded by a tooth having the character of a true molar ; this is 

 the only one comparable to the milk-teeth of the higher 

 mammalia ; all the other teeth remain unchanged. 



