BDBNTATE MAMMALS. 577 



themselves. Their food is roots, poultry, or wild fruits. 

 They liave no hair on their tails, but a sort of a scale or 

 hard crust, as the beavers have. If a cat has nine lives, 

 this creature surely has nineteen ; for if you break every 

 bone in their skin and mash their skull, leaving them for 

 dead, you may come an hour after and they will be gone 

 quite away, or perhaps you may meet them creeping away. " 

 (" Perfect Description of Virginia," 1649.) 



There are squirrel-like flying marsupials {Petaurus), 

 marsupial rats, marsupial bears, and marsupial ant-eaters 

 {MyrmecoUus), but the most characteristic Australian ani- 

 mals are the diiffierent kinds of kangaroo {Macropiis thetidis, 

 Fig. 498). 



The largest species, M. giganteus Shaw, is, 1-8 metres, or 

 nearly six feet long. Kangaroos go in herds, and move by 

 a succession of long leaps. 



All marsupials are stupid, low in intelligence, and, in the 

 insectivorous and carnivorous forms, of vicious temper. 

 With the exception of the opossums, all are confined to Aus- 

 tralia, New Zealand, and New Guinea. 



Sub-class 3. MonodelpMa. — While in the marsupials the 

 termination of the oviduct is double," in the present group 

 it is always single, whence the name MonodelpMa. The 

 members of the group are also called placental Mammalia, 

 because the young at birth are of considerable size and 

 nearly perfect in development, being nourished until born 

 by a highly vascular mass or thick membrane {placenta) 

 supplied with arteries and veins, developed originally from 

 the allantois, which is a temporary embryonic membrane. 

 The brain, as a rule, presents an advance over that of any 

 of the preceding mammals, the corpus Mllosum being better 

 developed, while the anterior commissures are all reduced. 

 There are no marsupial bones, though in some Carnivora 

 certain small cartilages appear to represent them. 



There are twelve orders, as follows : 



Order 1. Bruta or Edentata. — These creatures, repre- 

 sented by the sloths, ant-eaters, pangolins, and armadillos, 

 stand next above the non-placentals or marsupials, as the 

 brain is but little better developed, the hemispheres in some 



