70 



THE AUSTRALIAN MUSEUM MAGAZINE. 



The 'Possum, slaughtered in millions for its 

 valuable fur, is representative of the tree, 

 climbing types. 

 Photo from Life — -G. C. Cluttoii. 



PARALLELISM IN DEVELOPMENT. 



In other lands the various life spheres 

 are occupied by distinct orders of mam- 

 mals; thus the grass-eating mammals 

 form one order, the flesh-eaters another. 

 But in Australia the 

 single marsupialj or- 

 der has been adapt- 

 ed in the most mar- 

 vellous manner for 

 the most diverse 

 roles, so that the 

 distinct orders of 

 the old world are 

 parelleled in Aus- 

 tralia by various 

 modifications of the 

 one order available. 

 Thus the kangaroos 

 and wallabies may 

 be regarded as the 

 Australian repre- 

 sentatives of grass- 

 eaters such as the 

 hoofed mammals, 

 while the native 

 cats, Tasmanian de- 

 vil, and Tasmanian 

 wolf parallel the 

 cats, dogs, and 

 bears of other 

 countries. 



Animals which have similar modes of 

 life develop a similarity in form; no 

 better example of this can be instanced 

 than the striking resemblance in outward 

 form l)etween a whale and a fish. Now 

 when we compare marsupials with paral- 

 lel forms among placental mammals we 

 find some very remarkable resemlilances, 

 as is clearly indicated by the names 

 given to the native fauna of Australia 

 Ijy the early settlers, who were so struck 

 ])y their similarity to the animals with 

 which they had been familiar at home. 

 The marsupial mouse so strongly re- 

 seml)les the common house mouse in out- 

 ward appearance that it seemed per- 

 fectly natural to regard the two as close 

 relatives. Yet the common mouse is a 

 placental, and is more closely related to 

 the giraffe than to the marsupial mouse, 

 wliicli, on the other hand, is a near re- 

 lative of the kangaroo and the native 

 liear, as is clearly seen from its skeletal 

 and anatomical features. So the Tas- 

 manian Avolf presents a strong similar- 

 ity to the northern Avolf, because its 

 mode of life and method of procuring 

 and dealing with food is the same, yet 

 in its internal structure it is closely al- 

 lied, not to the common wolf, but to the 

 pouched mouse, the marsupial mole and 



The King-tailed 'Possum builds a nest or drey of twigs and ferns, 



I'lioto. — .G. r. Clutton. 



