CHAPTER XVI 



Order XI. Monotremata 



WHETHER the few remaining mammals should be 

 classed with the marsupials, or should form a 

 separate order, was long a disputed point. In the mar- 

 supials the young are brought into the world while they 

 are in an abnormally early and helpless stage. But there 

 are mammals on a still lower rung of the evolutional ladder, 

 whose young are brought into the world in the shape of eggs 

 in one case deposited in an underground burrow, and in 

 the other carried about in the pouch of the parent until the 

 young are hatched. From that time their existence is con- 

 tinued exactly as in the case of the young marsupials. 



The Monotremes, of which there are only two distinct 

 family types, in the one aspect of egg-laying lean towards 

 the reptiles, but in other respects are true mammals. They 

 may be viewed as composites, links between the Mammalia 

 and Reptilia. In any case their peculiar position merits the 

 placing of them in an order of their own. 



ECHIDNA (Echidna aculeata). 

 Plate XLVII. Fig. i. 



The Echidna, or Porcupine Ant-eater, a native of Australia, 

 is quite an extraordinary creature. About a foot in length, 

 it is much like a hedgehog, except that its spines are larger 

 and stronger and are set in a coat of silky, chestnut-coloured 

 hair. Its head is small, with a slender and very elongated 

 muzzle. The mouth is small and toothless, but the tongue 



453 



