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THE AUSTRALIAN MUSEUM MAGAZINE. 



whiei: still lay eggs, a very ancient 

 method of bringing forth young, which 

 was probably at one time characteristic 

 of all back-boned animals. In spite of 

 this old-fashioned custom of theirs the 

 inonotremes suckle their young and are 

 therefore true mammals. The fur of the 

 platypus is very valuable, but, as it is 

 an aquatic animal, and very alert, and 

 is, moreover, stringently protected, it is 

 probably in no immediate danger of ex- 

 tinction; nor is the echidna, which is 

 Avell defended by its sharp spines, and 

 is not useful in any way, although to 

 the blaekfellow it is an article of diet. 

 Were these two animals to become ex- 

 tinct the whole scientific world would 

 be filled with keen regret, but, as Grant 

 Allen says in his sprightly verse: — 



Although in unanimous chorus 



We mourn that, from ages before us, 



No single linaliosaiirHs to day should 



survive. 

 Yet joyfully may we bethink us, 

 With the earliest mammal to link us, 

 We still have the OrnHhorhyiuInis, 

 Extant and alive. 



MARSUPIALS. 



These, exemplified by the kangaroo, 

 wombat, bandicoot and many others, 

 form the second great group, and, as 

 their name implies, they are provided 

 in the female with a pouch or marsu- 

 piiim in which the young are carried. 

 Marsupials are the distinctive Austra- 

 lian manunals, and, except for the Ame- 

 rican opossums and the highly interesting 

 Caenolestes of South America, they have 

 no surviving relatives. In past geologi- 

 cal ages the members of this primitive 

 Order were more widely distributed, but, 

 with the rise of a more modern mam- 

 malian type, better equipped for the 

 battle of life, they gradually dwindled. 

 They crossed into Australia while that 

 continent was united to, or at any rate 

 less widely sejiarated from, the rest of 

 the woi'ld than it is now, and, as the 

 bridge by which they came was sub- 

 merged before the higher types could 

 follow, they have found sanctuary in 

 Australia and its adjacent islands frt)m 

 the fierce competition which all but ex- 

 terminated their kind in other countries. 

 Thus Australia became a marsupial pre- 

 serve. 



BIRTH OF THE MARSUPIAL. 



One striking difference between mar- 

 sui)ials and the higher mammals lies in 

 the fact that the young marsupial is 

 born in a very helpless innnature con- 

 dition. A full-grown kangaroo may 

 be six feet in lieit^ht, vet its new-born 



A newly-born Great Grey Kangaroo, attached 

 to a teat in its mother's pouch. Its fore 

 limbs are abnormally long and provided with 

 claws which are wanting on the weaker hind 

 limbs. 

 Photo.^^J. C. Clutton. 



young is no larger than one's thumb. 

 As soon as it is born the tiny creature 

 becomes transferred to its mother's 

 pouch, where it becomes firmly attached 

 to a teat and remains there perhaps for 

 months. The manner in which this 

 transference is effected is still under dis- 

 cussion. It has been observed that the 

 young of the Vii-ginian opossum are 

 born with abnormally long fore-legs, 

 armed with shai'p claws, by means of 

 Avhich they crawl up their mother's body 

 and enter the pouch. The same thing 

 is probably true of the kangaroo, for 

 its young also has elongated fore-limbs 

 a4'med with claws which are absent on 

 the toes of the hind feet. 



ADAPTIVE RADIATION. 



In nature there are a number of niches, 

 or particular conditions of life which 

 are suitable for such animals and plants 

 as have become adapted for them. Every 



