24 o AUSTRALIAN AND TASMANIAN ANIMALS 



it may be well to notice that the duck-like, horny beak of the platypus is in no 

 wise indicative of affinity with birds, but is merely a special adaptation to a 

 peculiar mode of life ; the same being true with regard to the slender, tooothless 

 beak of the spiny anteaters, which in some degree recalls the equally toothless 

 jaws of their South American namesakes. 



The eggs of both the platypus and the spiny anteaters, in comparison with 

 the foetal eggs of placental mammals, are remarkably large : they have leathery 

 or parchment-like shells, resembling those of reptiles, and are hatched like those 

 of birds. The temperature of the blood in both the spiny anteaters and the 

 platypus is distinctly lower than in other mammals and birds, and subject to great 

 fluctuations — circumstances which point to a near relationship between the egg- 

 laying mammals and the lower vertebrates. It was at one time supposed that the 

 nearest relatives of these strange creatures are the pouched mammals, since both 

 groups possess the so-called " marsupial bones," and are without the fully- 

 developed placenta of the higher mammals; but doubt has been thrown on the 

 nearness of the relationship, and the absence of teats, coupled with the totally 

 different structure of the milk-glands, certainly indicates the much lower grade of 

 the egg-laying as compared with the pouched mammals. In the former group the 

 milk-glands having no nipples, that is to say, no continuation of the skin serving 

 as outlets for the milk which can be grasped by the mouth of the suckling, the 

 young have to suck up the milk as it oozes to the surface from the glands them- 

 selves through sieve-like pores in the skin. These animals are therefore only 

 mammals in the sense that they yield milk, although they are not suckling 

 mammals in the proper sense of that term. 



Of the two groups of egg-laying mammals, the spiny anteaters, forming the 

 family Echiclniclce, or Tacky glossidce, are characterised by the rounded head 

 terminating in a long, thin, beak-like muzzle covered with hairless skin and 

 having at its tip the minute nostrils and small mouth. There are no external ears, 

 but the eyes are fairly large, although the head is very small in comparison with 

 the stout body. The short and stumpy tail is clothed with hairless skin ; and the 

 short and sturdy legs are furnished with remarkably powerful claws, those of the 

 hind-feet being turned outwards and backwards when walking. The feet and 

 under part of the body of the spiny anteaters are the only portions covered with 

 hair, the back being protected by rather short thick spines. The ' palate and 

 tongue are covered with small spines, and the surface of the brain is somewhat 

 complexly convoluted. In the common spiny anteater (Echidna, or Tachyglossus, 

 acideata) the spines are very like those of a hedgehog, but stouter and longer. 

 Like hedgehogs, these animals can roll themselves up into the shape of a ball by 

 means of powerful skin muscles. In habits they are harmless creatures, whose only 

 means. of defence are their spines. It has indeed been supposed that a peculiar 

 spine on the hind-leg of the male is used as a weapon, but it is probably employed 

 for another purpose. In spite of their enormously powerful burrowing claws the 

 legs are never used for offence ; the claws being employed solely for burying their 

 owner in the ground when threatened by danger, or for burrowing in search of insects 

 and their larvae and digging out and plundering ant-hills. The spiny anteaters seize 

 their living prey in the same manner as other animals whose diet is similar, such as 



